high-pressure synthesis and ferrimagnetic ordering of the b site-...

High-Pressure Synthesis and Ferrimagnetic Ordering of the B‑Site-Ordered Cubic Perovskite Pb2FeOsO6Qing Zhao,† Min Liu,† Jianhong Dai,† Hongshan Deng,† Yunyu Yin,† Long Zhou,† Junye Yang,†

Zhiwei Hu,‡ Stefano Agrestini,‡ Kai Chen,§ Eric Pellegrin,⊥ Manuel Valvidares,⊥ Lucie Nataf,∥

Franco̧is Baudelet,∥ L. H. Tjeng,‡ Yi-feng Yang,†,# Changqing Jin,†,# and Youwen Long*,†,#

†Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190,China‡Max-Planck Institute for Chemical Physics of Solids, Nothnitzer Straße 40, 01187 Dresden, Germany§Institute of Physics II, University of Cologne, Zulpicher Straße 77, 50937 Cologne, Germany⊥ALBA Synchrotron Light Source, E-08290 Cerdanyola del Valles, Barcelona, Spain∥Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France#Collaborative Innovation Center of Quantum Matter, Beijing 100190, China

ABSTRACT: Pb2FeOsO6 was prepared for the first time by using high-pressureand high-temperature synthesis techniques. This compound crystallizes into a B-site-ordered double-perovskite structure with cubic symmetry Fm3 ̅m, where theFe and Os atoms are orderly distributed with a rock-salt-type manner. Structurerefinement shows an Fe−Os antisite occupancy of about 16.6%. Structuralanalysis and X-ray absorption spectroscopy both demonstrate the chargecombination to be Pb2Fe

3+Os5+O6. A long-range ferrimagnetic transition is foundto occur at about 280 K due to antiferromagnetic interactions between theadjacent Fe3+ and Os5+ spins with a straight (180°) Fe−O−Os bond angle, asconfirmed by X-ray magnetic circular-dichroism measurements. First-principlestheoretical calculations reveal the semiconducting behavior as well as theFe3+(↑)Os5+(↓) antiferromagnetic coupling originating from the superexchangeinteractions between the half-filled 3d orbitals of Fe and t2g orbitals of Os.

1. INTRODUCTION

B-site-ordered double-perovskite oxides with the chemicalformula A2BB′O6 have been studied widely in the past decade.Compared with the simple ABO3 perovskite, both the B and B′sites in this ordered one accommodate transition metals, asshown in Figure 1.1 As a result, some peculiar magnetic and

electrical interactions may occur via B−B, B′−B′, and/or B−B′pathways, giving rise to many interesting physical propertiessuch as ferroelectricity, colossal magnetoresistance, half-metallicbehavior, and high-temperature spin ordering.2−6 A well-knownexample is Sr2FeMoO6, where a high ferromagnetic (FM)Curie temperature (TC = 420 K) and half-metallic transportproperties are observed, giving the material high potential foruse in spintronic devices above room temperature.7−9 Thisfascinating finding stimulates other investigations on B-site-ordered perovskites with 3d−4d (5d)-hybridized B−B′ chargecombinations. Subsequently, a ferrimagnetic (FiM) phasetransition is found to occur in Sr2CrOsO6, with the highestTC recorded (725 K) in perovskite oxides discovered to date.

4

Recently, the double-perovskite family of A2FeOsO6 (A =Ca, Ca0.5Sr0.5, and Sr) prepared under high pressure receivedspecial attention because of the exotic spin interactions. In thisfamily, the B-site Fe3+ and B′-site Os5+ ions are ordered with arock-salt-type manner. With decreasing A-site size, the crystalsymmetry is reduced from tetragonal I4/m (A = Sr) tomonoclinic P21/n (A = Ca0.5Sr0.5 and Ca) because of theincreasing octahedral distortion, with the average Fe−O−Os

Received: July 10, 2016Published: September 13, 2016

Figure 1. Crystal structure of a B-site-ordered double perovskite withspace group Fm3̅m. The B/B′-site transition metals form B/B′O6octahedra.

Article

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© 2016 American Chemical Society 9816 DOI: 10.1021/acs.inorgchem.6b01649Inorg. Chem. 2016, 55, 9816−9821

pubs.acs.org/IChttp://dx.doi.org/10.1021/acs.inorgchem.6b01649

bond angle 165.3° for Sr, 158.9° for Sr0.5Ca0.5, and 150.9° forCa.10−12 Because there exist lattice instability as well as multiplecompeting magnetic superexchange interactions in thetetragonal Sr2FeOsO6, two successive antiferromagnetic(AFM) phase transitions take place in this compound.13,14 Incontrast, only a single FiM ordering arising from the AFMcoupling between the Fe3+ and Os5+ spin sublattices is observedin the monoclinic Ca2FeOsO6 and CaSrFeOsO6 with the Curietemperature TC ≈ 320 and 210 K, respectively.

14 Moreover,although the Fe−O−Os superexchange pathway in Ca2FeOsO6is more bent than that in CaSrFeOsO6, the former possesses ahigher spin-ordering temperature than the latter. Thesebehaviors deviate from the Goodenough−Kanamori (GK)rules,15,16 which predict FM interactions between the half-filledeg orbitals of Fe

3+ and empty eg orbitals of Os5+ electrons via

Fe−O−Os superexchange interactions, with the band angleroughly >145°. Furthermore, according to the GK criteria, astraighter interaction pathway is expected to enhance themagnetic phase-transition temperature. However, this is not thecase in Ca2FeOsO6 and CaSrFeOsO6.To further understand the complex magnetic properties of

the A2FeOsO6 family, it is desirable to obtain a member of thecubic perovskite structure (i.e., no octahedral distortion and abent Fe−O−Os interaction pathway). However, such aperovskite system has never been successfully prepared yet.We thus adopt a larger-size cation Pb to substitute for the Asite, and a new B-site-ordered perovskite, Pb2FeOsO6 (PFOO),with cubic symmetry is obtained for the first time. To stabilizethe cubic perovskite structure of PFOO with a large A-sitecation, high pressure is necessary for sample synthesis. Similarto the monoclinic A = Ca and Sr0.5Ca0.5 members, the cubicPFOO also shows a single FiM phase transition at about 280 K.

2. EXPERIMENTAL AND CALCULATION SECTIONPolycrystalline PFOO was prepared by using a solid-state reactionmethod under high-pressure and high-temperature conditionsimplemented on a cubic-anvil-type high-pressure apparatus. Thestarting materials that we used were high-purity (>99.9%) PbO, PbO2,Fe2O3, and OsO2 powders. The powders with a stoichiometric moleratio of 3:1:1:2 were thoroughly mixed in an agate mortar within anargon-filled glovebox and then sealed into a platinum capsule with 2.8mm diameter and 4.0 mm length. The capsule was treated at 8 GPaand 1673 K for 30 min. When the heating process was finished, thepressure was slowly released to ambient pressure.The phase quality and crystal structure of the high-pressure product

were characterized by powder X-ray diffraction (XRD) using a Huberdiffractometer with Cu Kα1 radiation at 40 kV and 30 mA. The XRDpattern was collected in the angle (2θ) range from 10° to 100° withsteps of 0.005° at room temperature. The data were analyzed byRietveld refinement using the GSAS program.17 X-ray absorption(XAS) and X-ray magnetic circular-dichroism (XMCD) spectroscopiesat the Fe-L2,3 edges were measured at the BL29 BOREAS beamline ofALBA synchrotron radiation facility in Barcelona using a total electronyield mode. The Os-L2,3 XAS and XMCD measurements wereperformed at the ODE beamline of SOLEIL in Paris usingtransmission mode. The Fe-L2,3 (Os-L2,3) XMCD signal was measured,with the sample kept at a temperature of 35 K (5 K) and in a magneticfield of 6 T (1.2 T). The Os-L3,2 edge-jump intensity ratio L3/L2 wasnormalized to 2.08.18 This takes into account the difference in theradial matrix elements of the 2p1/2-to-5d (L2) and 2p3/2-to-5d (L3)transitions. Magnetic susceptibility and magnetization were measuredusing a superconducting quantum interference device magnetometer(Quantum Design, MPMS-VSM). The magnetic susceptibility datawere collected between 2 and 400 K at different magnetic fields. Thefield dependence of magnetization at different temperatures wasmeasured under fields from −7 to +7 T. Electrical resistivity

measurements were performed by using a standard four-probe methodon a physical property measurement system (Quantum Design,PPMS-9T).

First-principles calculations were carried out using a full-potentiallinearized augmented plane-wave method, as implemented in theWIEN2K package.19 The used Muffin-tin radii were 2.50 au for Pb,2.00 au for Fe, 2.00 au for Os, and 1.60 au for O. The maximummodulus for the reciprocal vectors Kmax was chosen such that RMTKmax= 8.0. We took the generalized gradient approximation (GGA)exchange-correlation functional by the Perdew, Burke, and Ernzerhofexchange-correlation energy with an effective Ueff = 4 eV for Fe and 2eV for Os in the GGA+U calculations.20−22 A total of 1000 k-pointmeshes in the Brillouin zone were used in the calculations. The latticeparameters and atom positions obtained in the experiment (see Table1) were used for the calculations.

3. RESULTS AND DISCUSSIONFigure 2 shows the XRD pattern of PFOO measured at roomtemperature as well as the related structure refinement results.The diffraction peaks can be indexed on the basis of a cubicperovskite cell with lattice parameter a ≈ 2ap. Here ap indicatesthe lattice constant for a simple cubic ABO3 perovskite. The

Table 1. Refined Structural Parameters of PFOO and BVSValues for Fe and Os at Room Temperature.a,b

parameter PFOO

a (Å) 7.9187(2)Ox 0.2518(6)Uiso(Pb) (100 Å

2) 1.83(2)Uiso(Fe) (100 Å

2) 1.21(5)Uiso(Os) (100 Å

2) 0.69(2)Uiso(O) (100 Å

2) 2.5occupancy(Pb) 1.02(2)occupancy(Fe/Os) 0.834(1)/0.166(1)occupancy(Os/Fe) 0.834(1)/0.166(1)occupancy(O) 1.0Pb−O (×12) (Å) 2.7997(3)Fe−O (×6) (Å) 1.994(5)Os−O (×6) (Å) 1.965(5)BVS(Fe) 3.17BVS(Os) 4.61Rwp (%) 5.66Rp (%) 3.71

aSpace group: Fm3̅m. bThe BVS values (Vi) were calculated using theformula Vi = ∑jSij and Sij = exp[(r0 − rij)/b)]. The parameters ofr0(Fe

3+) = 1.759 Å, r0(Os5+) = 1.868 Å, and b = 0.37 were used in the

BVS calculation. For the B-site Fe and B′-site Os, six coordinated Oatoms were used.

Figure 2. XRD pattern and structure refinement results of PFOO. Theobserved (circles), calculated (line), and difference (bottom line) areshown. The ticks indicate the Bragg reflections allowed with spacegroup Fm3̅m. A small amount of uncertain impurities (∼5 wt %) wasexcluded from the pattern.

Inorganic Chemistry Article

DOI: 10.1021/acs.inorgchem.6b01649Inorg. Chem. 2016, 55, 9816−9821

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absence of a diffraction peak with h + k, k + l, and h + l = oddsuggests face-centering of the unit cell.23 The Rietveld analysisdemonstrates that PFOO crystallizes into a B-site-orderedperovskite structure with space group Fm3̅m. In this symmetry,all of the cations occupy fixed atomic positions at 8c (0.25, 0.25,0.25) for Pb, 4a (0, 0, 0) for Fe, and 4b (0.5, 0.5, 0.5) for Os,and the O is also located at a special site 24e (x, 0, 0).24 Thismeans that the only variable position parameter is Ox, whichdetermines the Fe−O and Os−O distances. The sharpdiffraction peaks with h + k + l = odd such as the (111) and(311) peaks reveal that the B-site Fe and B′-site Os are orderlydistributed in a rock-salt-type manner, as observed in otherA2FeOsO6 family members. The refined structural parametersare listed in Table 1. The lattice constant of PFOO (7.9187 Å)is slightly larger than the c axis (7.8867 Å) of the tetragonalSr2FeOsO6 because of the introduction of larger-size Pb ions atthe A site.10 Because X-ray is enough sensitive to distinguish thetransition metals Fe and Os, the degree of order for these twocations was characterized by refining the occupancy parameters.We find that there exists an Fe−Os antisite occupancy of about16.6%, while the occupancy for Pb is almost unified. Note thatthe Fe−Os order degree of PFOO is similar to that observed inCa2FeOsO6 and Sr2FeOsO6.

11,12,25

On the basis of the refined Fe−O and Os−O distances,bond-valence-sum (BVS) calculations give the valence state as3.17+ for Fe and 4.61+ for Os, suggesting an Fe3+/Os5+ chargecombination. Because XAS at the transition-metal L2,3 edges iselement-specific and highly sensitive to the valence state (anincrease of the valence state of the metal ion causes a shift ofthe XAS L2,3 edges toward higher energies),

26−28 this techniquewas used to confirm the valence states of Fe and Os. Figure 3a

shows the Fe-L2,3 XAS of PFOO together with the relatedreferences Fe0.04Mg0.096O and Fe2O3, with FeO6 octahedralcoordination similar to that of the Fe2+ and Fe3+ references,respectively.29 Obviously, PFOO and the Fe2+ referenceFe0.04Mg0.96O display essentially different spectral features.However, the Fe-L2,3 edges of PFOO are at the same energypositions as those of the Fe3+ standard Fe2O3, confirming thepresence of the Fe3+ state in PFOO. Furthermore, the multiplespectral feature of PFOO is very similar to that of Fe2O3,

indicating a high-spin state for Fe3+. Having determined an Fe3+

state in PFOO, we turn to the Os-L3 XAS to further confirmthe Os5+ state, as required for charge balance. The Os-L3 XASof PFOO along with Sr2FeOsO6 and La2MgOsO6 is shown inFigure 3b. By comparison with the Os4+ reference La2MgOsO6,the energy position of PFOO apparently shifts toward higherenergy and is almost located at the same position as that of theOs5+ reference Sr2FeOsO6. Therefore, like other A2FeOsO6members, the present PFOO also possesses the Fe3+/Os5+

charge combination at the perovskite B/B′ sites.Figure 4a shows the temperature dependence of magnetic

susceptibility measured at different fields using zero-field-

cooling (ZFC) and field-cooling (FC) modes. The suscepti-bility experiences a remarkable increase at TC ≈ 280 K,indicating a FM or FiM phase transition. At a lower field like0.1 T, the ZFC and FC curves considerably separate from eachother. However, when a higher field (e.g., 2 T) is applied toovercome the domain-wall energy, these two susceptibilitycurves become nearly overlapped. Above 300 K, the inversemagnetic susceptibility measured at 0.1 T can be well fitted onthe basis of the Curie−Weiss law, giving a positive Weisstemperature (θ = 273 K) that is comparable to the TC value, incoherence with the FM or FiM spin interactions.30 Accordingto the fitted Curie constant, the effective moment is calculatedto be μeff = 3.22 μB/fu. This value is much smaller than theexpected one (7.07 μB/fu) considering the spin-only con-tribution for the high-spin Fe3+ and Os5+. Because a high-spinFe3+ ion itself can generate a 5.92 μB/fu effective moment, thesignificantly reduced μeff value in the fitting probably isindicative of the presence of some short-range spin orderingabove TC, as mentioned in analogous perovskites.

31,32

The FM/FiM behavior of PFOO can be further characterizedby magnetization measurements. As presented in Figure 4b, thecanonical magnetic hysteresis curves observed below TC revealthe long-range FM or FiM ordering, as demonstrated from themagnetic susceptibility results mentioned above. At 2 K, thesaturated spin moment that we measured is about 1.6 μB/fu.Because the spin−orbit-coupling (SOC) effect of Os5+ is not

Figure 3. XAS of PFOO measured at room temperature for (a) theFe-L2, 3 and (b) Os-L3 edges. The XAS spectra of related references arealso shown for comparison.

Figure 4. (a) Temperature dependence of magnetic susceptibility (χ)measured at 0.1 and 2 T. The solid line in the inset shows the Curie−Weiss fitting above 300 K. (b) Field-dependent magnetizationmeasured at different temperatures for PFOO.



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significant due to the d3-electron configuration,22 the collinearFe3+(↑)Os5+(↑) FM coupling will produce an 8.0 μB saturationmoment in each formula unit, in the assumption of a local-electron model without considering the SOC. Clearly, thisvalue is unreasonably larger than the experimental observation.On the other hand, the collinear Fe3+(↑)Os5+(↓) FiM couplinggives a saturated moment (2.0 μB/fu) that is comparable withthe measurement result at 2 K. The Fe−Os antisite effectidentified by XRD refinement should be responsible for thereduced spin moment observed in the experiment. Wetherefore conclude that PFOO experiences a FiM phasetransition around 280 K.In addition, the Fe3+(↑)Os5+(↓) FiM coupling can be further

confirmed by XMCD measurements at the Fe- and Os-L2,3edges. Figure 5 shows the XAS (μ+ and μ−) as well as the

resulting XMCD (Δμ = μ+ − μ−) spectra for Fe3+ and Os5+.Here μ+ and μ− represent different photon helicities paralleland antiparallel to the applied magnetic field, respectively. Onecan find that the XMCD signal is negative for the Fe-L3 edgebut positive for the Os-L3 edge. On the contrary, it becomespositive for the Fe-L2 edge but negative for the Os-L2 edge. Theopposite signs of the XMCD spectra at the Fe- and Os-L2,3edges reveal that AFM coupling occurs between the Fe3+ andOs5+ magnetic sublattices, leading to the long-range Fe3+(↑)-Os5+(↓) FiM spin alignment. The observed line shapes of Fe-and Os-L2,3 XMCD spectra of PFOO are very similar to thoseof Ca2FeOsO6 and Sr2FeOsO6.

33 It is very interesting that themuch smaller dichroic signal of the Os-L3 edge compared tothat of the Os-L2 edge provides direct evidence for the presenceof a substantial orbital moment that is oriented antiparallel tothe spin moment. At the XMCD measurement conditions weused, PFOO is not magnetically saturated; we thus cannot usethe orbital and spin sum rules to obtain the orbital and spinquantum numbers ⟨Lz⟩ and ⟨Sz⟩. However, the sum rule ⟨Lz⟩/2⟨Sz⟩(1 + 7⟨Tz⟩/2⟨Sz⟩) = 2∑Δμ(L3 + L2)/3[∑Δμ(L3) −2ΣΔμ(L2)] does not depend on the experimental conditions.Using the theoretical value of 7⟨Tz⟩/2⟨Sz⟩ = −0.23 obtained inA2FeOsO6,

33 we get ⟨Lz⟩/2⟨Sz⟩ = −0.16 for PFOO. This valueis somewhat larger than that of Ca2FeOsO6 and Sr2FeOsO6

(−0.099), implying a stronger orbital moment in the cubicPFOO than that of the distorted analogues.The temperature-dependent resistivity of PFOO is shown in

Figure 6. With decreasing temperature, the resistivity of PFOO

gradually increases from 300 to 2 K, indicating a semi-conducting conductivity behavior. The temperature depend-ence of the resistivity between 250 and 300 K can be fittedusing the thermal activation model with the formula ρ = ρ0exp(EA/kBT), as shown in the inset of Figure 6. Here EA and kBstand for the thermal activation energy and Boltzmannconstant, respectively. The fitting yielded EA = 14 meV,implying an energy band gap of about 28 meV. However,because of the Fe−Os antisite (16.6%) effect, this smallactivation energy cannot reasonably reflect the real energy bandgap for a completely B-site-ordered PFOO. As shown later,theoretical calculations indicate a 170 meV band gap.First-principles theoretical calculations were performed to

gain deeper insight into the magnetic and electrical propertiesof PFOO. First, we calculated different magnetic configurationsbetween Fe and Os ions, as observed in the reported A2FeOsO6family. It was found that both C- and G-type AFM structureshave comparable and most favorable system energies. Becausethe C-type AFM structure does not generate any net spinmoment, which deviates from experimental observation, the G-type AFM structure is used to calculate the electronicproperties. In our GGA+U calculations, the magnetic momentwas calculated to be 4.12 μB for each Fe, −1.60 μB for each Os,−0.027 μB for each O, and −0.358 μB in the interstitial. Thetotal spin moment is thus 2.00 μB/fu, which is well inagreement with the experimental result observed at 2 K byconsidering the Fe−Os antisite.Figure 7 shows the calculated electronic band structures and

the partial densities of states (DOSs) of PFOO. Thecalculations show an indirect energy band gap of 170 meV,revealing the semiconducting nature. Note that the gapmagnitude is overestimated, as is often expected for GGA+Ucalculations. Because all of the Fe−O−Os bondings are straight(180°) in the cubic perovskite PFOO, this compound possessesthe smallest energy gap in the A2FeOsO6 family (∼2.4 eV forCa2FeOsO6 and ∼0.25 eV for Sr2FeOsO6).

10,11 As seen fromthe orbital-resolved DOSs in Figure 7, near the Fermi level, theelectronic states are dominated by the 3d electrons of Fe as wellas the Os t2g electrons, whereas the empty Os eg orbitals arelocated far away from the Fermi level. Therefore, the spininteractions will mainly take place between the half-filled 3dorbitals of Fe and t2g orbitals of Os, giving rise to an AFMcoupling between the Fe3+ and Os5+ magnetic sublattices viastraight Fe−O−Os superexchange interaction pathways. As aresult, a FiM instead of FM ordering occurs in the present

Figure 5. XAS with helicity parallel (μ+ black line) and antiparallel (μ−

red line) to the applied magnetic field and the corresponding XMCDsignal μ+ − μ− (blue line) for PFOO at (a) Fe- and (b) Os-L2,3 edges.For clarity, the XMCD signal of Os in part b was enlarged by 40 times.

Figure 6. Temperature dependence of the resistivity (ρ) of PFOO.The solid line in the inset shows the fitting result using the thermalexcitation model between 250 and 300 K.



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PFOO. Note that Fe−Os antiferromagnetic interactions arealso observed in a both A- and B-site-ordered cubic quadrupleperovskite CaCu3Fe2Os2O12.

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4. CONCLUSIONIn summary, a novel oxide PFOO was synthesized at 8 GPa and1673 K. The compound crystallizes into a B-site-orderedperovskite structure with space group Fm3 ̅m. This is the firstexample of a cubic crystal system in the B-site-orderedperovskite family A2FeOsO6. Both BVS calculations and XASmeasurements indicate a Pb2Fe

3+Os5+O6 charge combinationwith rock-salt-type ordered distribution between the Fe3+

(t2g3eg

2; S = 5/2) and Os5+ (t2g

3eg0; S = 3/2) ions. A FiM

phase transition caused by the antiferromagnetically coupledFe3+ and Os5+ spin sublattices occurs near room temperature(TC ≈ 280 K). At 2 K, the saturation spin moment observed inthe experiment is 1.6 μB/fu, in accordance with the Fe

3+(↑)-Os5+(↓) FiM coupling, by considering the Fe−Os antisiteoccupancy (∼16.6%). The XMCD spectroscopy providesfurther evidence for this FiM ordering. On the basis of thewell-known GK rules, a long-range FM ordering is expected tooccur between the half-filled eg orbitals of Fe

3+ and the emptyeg orbitals of Os

5+ via straight (180°) Fe−O−Os interactionpathways in the cubic PFOO. Our theoretical calculations,however, reveal that the empty eg orbitals of Os

5+ are far awayfrom the Fermi level. As a result, the half-filled t2g orbitals ofOs5+ instead of the empty eg take part in the spinsuperexchange interactions with the half-filled 3d orbitals ofFe, leading to AFM interactions between Fe3+ and Os5+ spins.

■ AUTHOR INFORMATIONCorresponding Author*E-mail: [email protected] authors declare no competing financial interest.

■ ACKNOWLEDGMENTSThis work was supported by the 973 Project of the Ministry ofScience and Technology of China (Grant 2014CB921500), theStrategic Priority Research Program of the Chinese Academy ofSciences (Grant XDB07030300), and the National NaturalScience Foundation of China (Grant 11574378). K.C.

benefited from the support of the German funding agencyDFG (Project 615811).

■ REFERENCES(1) King, G.; Woodward, P. M. Cation ordering in perovskites. J.Mater. Chem. 2010, 20, 5785−5796.(2) Kimura, T.; Goto, T.; Shintani, H.; Ishizaka, K.; Arima, T.;Tokura, Y. Magnetic control of ferroelectric polarization. Nature 2003,426, 55−58.(3) Salamon, M. B.; Jaime, M. The physics of manganites: Structureand transport. Rev. Mod. Phys. 2001, 73, 583−628.(4) Krockenberger, Y.; Mogare, K.; Reehuis, M.; Tovar, M.; Jansen,M.; Vaitheeswaran, G.; Kanchana, V.; Bultmark, F.; Delin, A.; Wilhelm,F.; Rogalev, A.; Winkler, A.; Alff, L. Sr2CrOsO6: End point of a spin-polarized metal-insulator transition by 5 d band filling. Phys. Rev. B:Condens. Matter Mater. Phys. 2007, 75, 020404.(5) Alamelu, T.; Varadaraju, U. V.; Venkatesan, M.; Douvalis, A. P.;Coey, J. M. D. Structural and magnetic properties of (Sr2‑xCax)FeReO6. J. Appl. Phys. 2002, 91, 8909−8911.(6) Kato, H.; Okuda, T.; Okimoto, Y.; Tomioka, Y.; Takenoya, Y.;Ohkubo, A.; Kawasaki, M.; Tokura, Y. Metallic ordered double-perovskite Sr2CrReO6 with maximal Curie temperature of 635 K. Appl.Phys. Lett. 2002, 81, 328−330.(7) Tokura, Y.; Kobayashi, K.-I.; Kimura, T.; Sawada, H.; Terakura,K. Room-temperature magnetoresistance in an oxide material with anordered double-perovskite structure. Nature 1998, 395, 677−680.(8) Tomioka, Y.; Okuda, T.; Okimoto, Y.; Kumai, R.; Kobayashi, K.-I.; Tokura, Y. Magnetic and electronic properties of a single crystal ofordered double perovskite Sr2FeMoO6. Phys. Rev. B: Condens. MatterMater. Phys. 2000, 61, 422−427.(9) Serrate, D.; Teresa, J. M. De; Ibarra, M. R. Double perovskiteswith ferromagnetism above room temperature. J. Phys.: Condens.Matter 2007, 19, 023201.(10) Paul, A. K.; Jansen, M.; Yan, B.; Felser, C.; Reehuis, M.; Abdala,P. M. Synthesis, crystal structure, and physical properties ofSr2FeOsO6. Inorg. Chem. 2013, 52, 6713−6719.(11) Feng, H. L.; Arai, M.; Matsushita, Y.; Tsujimoto, Y.; Guo, Y.;Sathish, C. I.; Wang, X.; Yuan, Y.; Tanaka, M.; Yamaura, K. High-temperature ferrimagnetism driven by lattice distortion in doubleperovskite Ca2FeOsO6. J. Am. Chem. Soc. 2014, 136, 3326−3329.(12) Morrow, R.; Freeland, J. W.; Woodward, P. M. Probing theLinks between Structure and Magnetism in Sr2−xCaxFeOsO6 DoublePerovskites. Inorg. Chem. 2014, 53, 7983−7992.(13) Paul, A. K.; Reehuis, M.; Ksenofontov, V.; Yan, B.; Hoser, A.;Tobbens, D. M.; Abdala, P. M.; Adler, P.; Jansen, M.; Felser, C. LatticeInstability and Competing Spin Structures in the Double PerovskiteInsulator Sr2FeOsO6. Phys. Rev. Lett. 2013, 111, 167205.(14) Hou, Y. S.; Xiang, H. J.; Gong, X. G. Lattice-distortion InducedMagnetic Transition from Low-temperature Antiferromagnetism toHigh-temperature Ferrimagnetism in Double PerovskitesA2FeOsO6(A = Ca, Sr). Sci. Rep. 2015, 5, 13159.(15) Goodenough, J. B. Theory of the Role of Covalence in thePerovskite-Type Manganites [La, M (II)]MnO3. Phys. Rev. 1955, 100,564−573.(16) Kanamori, J. Superexchange interaction and symmetry proper-ties of electron orbitals. J. Phys. Chem. Solids 1959, 10, 87−98.(17) Larson, A. C.; Dreele, R. B. V. Los Alamos National LaboratoryReport No. LAUR 86-748, 2004.(18) Henke, B. L.; Gullikson, E. M.; Davis, J. C. X-Ray Interactions:Photoabsorption, Scattering, Transmission, and Reflection at E = 50−30,000 eV, Z = 1−92. At. Data Nucl. Data Tables 1993, 54, 181.(19) Blaha, P.; Schwarz, K.; Madsen, G.; Kvasnicka, D.; Luitz, J. J.Endocrinol. 2001, 196, 123−30.(20) Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradientapproximation made simple. Phys. Rev. Lett. 1996, 77, 3865.(21) Kanungo, S.; Yan, B.; Jansen, M.; Felser, C. Ab initio study oflow-temperature magnetic properties of double perovskite Sr2FeOsO6.Phys. Rev. B: Condens. Matter Mater. Phys. 2014, 89, 214414.

Figure 7. First-principles numerical results for the band structures andpartial DOSs of PFOO.



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(22) Wang, H.; Zhu, S.; Ou, X.; Wu, H. Ferrimagnetism in thedouble perovskite Ca2FeOsO6: A density functional study. Phys. Rev.B: Condens. Matter Mater. Phys. 2014, 90, 054406.(23) Mezzadri, F.; Delmonte, D.; Orlandi, F.; Pernechele, C.;Calestani, G.; Solzi, M.; Lantieri, M.; Spina, G.; Cabassi, R.; Bolzoni,F.; Fittipaldi, M.; Merlini, M.; Migliori, A.; Manuel, P.; Gilioli, E.Structural and magnetic characterization of the double perovskitePb2FeMoO6. J. Mater. Chem. C 2016, 4, 1533−1542.(24) Patwe, S. J.; Achary, S. N.; Mathews, M. D.; Tyagi, A. K.Synthesis, phase transition and thermal expansion studies onM2MgWO6 (M= Ba

2+ and Sr2+) double perovskites. J. Alloys Compd.2005, 390, 100−105.(25) Feng, H. L.; Tsujimoto, Y.; Guo, Y.; Sun, Y.; Sathish, C. I.;Yamaura, K. High pressure synthesis, crystal structure, and magneticproperties of the double-perovskite Sr2FeOsO6. High Pressure Res.2013, 33, 221−228.(26) Mandal, T. K.; Croft, M.; Hadermann, J.; Van Tendeloo, G.;Stephens, P. W.; Greenblatt, M. La2MnVO6 double perovskite: astructural, magnetic and X-ray absorption investigation. J. Mater. Chem.2009, 19, 4382−4390.(27) Hollmann, N.; Valldor, M.; Wu, H.; Hu, Z.; Qureshi, N.;Willers, T.; Chin, Y.-Y.; Cezar, J. C.; Tanaka, A.; Brookes, N. B.; Tjeng,L. H. Orbital occupation and magnetism of tetrahedrally coordinatediron in CaBaFe4O7. Phys. Rev. B: Condens. Matter Mater. Phys. 2011,83, 180405.(28) Burnus, T.; Hu, Z.; Wu, H.; Cezar, J. C.; Niitaka, S.; Takagi, H.;Chang, C. F.; Brookes, N. B.; Lin, H.-J.; Jang, L. Y.; Tanaka, A.; Liang,K. S.; Chen, C. T.; Tjeng, L. H. X-ray absorption and x-ray magneticdichroism study on Ca3CoRhO6 and Ca3FeRhO6. Phys. Rev. B:Condens. Matter Mater. Phys. 2008, 77, 205111.(29) Haupricht, T.; Sutarto, R.; Haverkort, M. W.; Ott, H.; Tanaka,A.; Hsieh, H. H.; Lin, H. − J.; Chen, C. T.; Hu, Z.; Tjeng, L. H. Localelectronic structure of Fe2+ impurities in MgO thin films: Temper-ature-dependent soft x-ray absorption spectroscopy study. Phys. Rev. B:Condens. Matter Mater. Phys. 2010, 82, 035120.(30) Li, M.; Retuerto, M.; Deng, Z.; Stephens, P. W.; Croft, M.;Huang, Q.; Wu, H.; Deng, X.; Kotliar, G.; Sanchez-Benitez, J.;Hadermann, J.; Walker, D.; Greenblatt, M. Giant Magnetoresistance inthe Half-Metallic Double-Perovskite Ferrimagnet Mn2FeReO6. Angew.Chem., Int. Ed. 2015, 54, 12069−12073.(31) Winkler, A.; Narayanan, N.; Mikhailova, D.; Bramnik, K. G.;Ehrenberg, H.; Fuess, H.; Vaitheeswaran, G.; Kanchana, V.; Wilhelm,F.; Rogalev, A.; Kolchinskaya, A.; Alff, L. Magnetism in Re-basedferrimagnetic double perovskites. New J. Phys. 2009, 11, 073047.(32) Wu, H. Electronic structure study of double perovskitesA2FeReO6 (A= Ba, Sr, Ca) and Sr2MMoO6 (M= Cr, Mn, Fe, Co) byLSDA and LSDA+ U. Phys. Rev. B: Condens. Matter Mater. Phys. 2001,64, 125126.(33) Veiga, L. S. I.; Fabbris, G.; van Veenendaal, M.; Souza-Neto, N.M.; Feng, H. L.; Yamaura, K.; Haskel, D. Fragility of ferromagneticdouble exchange interactions and pressure tuning of magnetism in 3d− 5 d double perovskite Sr2FeOsO6. Phys. Rev. B: Condens. MatterMater. Phys. 2015, 91, 235135.(34) Deng, H. S.; Liu, M.; Dai, J. H.; Hu, Z. W.; Kuo, C.; Yin, Y. Y.;Yang, J. Y.; Wang, X.; Zhao, Q.; Xu, Y. J.; Fu, Z. M.; Cai, J. W.; Guo,H. Z.; Jin, K. J.; Pi, T.; Soo, Y.; Zhou, G. H.; Cheng, J. G.; Chen, K.;Ohresser, P.; Yang, Y. F.; Jin, C. Q.; Tjeng, L. H.; Long, Y. W. Strongenhancement of spin ordering by A-site magnetic ions in theferrimagnet CaCu3Fe2Os2O12. Phys. Rev. B: Condens. Matter Mater.Phys. 2016, 94, 024414.

■ NOTE ADDED AFTER ASAP PUBLICATIONThis paper was published on the Web on September 13, 2016,with errors in Figure 5. The corrected version was reposted onSeptember 15, 2016.



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