Magnetism in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Sr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>CrMoO</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math>: A combined<i>ab initio</i>and model study

Sanyal, Prabuddha; Halder, Anita; Si, Liang; Wallerberger, Markus; Held, Karsten; Saha‐Dasgupta, Tanusri

doi:10.1103/physrevb.94.035132

Cited by 28 publications

(14 citation statements)

References 58 publications

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“…where, the last term incorporates the superexchange interaction between the intrinsic spin residing at B' site and the core spin at B site. While this term is non-zero for compounds like Sr 2 CrReO 6 , Sr 2 CrOsO 6 [9], Sr 2 CrMoO 6 [19], it is zero for compounds like Sr 2 FeMoO 6 [8], or Sr 2 CrWO 6 [9], Ba 2 FeReO 6 [17]. We note the above model Hamiltonian does not take into accounte the effect of spin-orbit coupling present at 4d/5d TM sites.…”

Section: A S a S A S A S A Am Mu Anmentioning

confidence: 97%

“…The strong hybridization between Cr and W states, as evidenced in the plot of effective W Wannier function taking into account Cr-W hybridization, pushes the W t 2g down spin states down and the W t 2g up spin states up, resulting in an effective spin splitting at W site which is oppositely oriented to the intrinsic spin splitting at Cr site. This mechanism can be mathematically formulated in terms of a two sublattice double-exchange model [18], consisting of large core (classical) spin at magnetic site, strong coupling at the magnetic site between the core spin and the itinerant electron, and delocalization of the itinerant electron on the B-B' network, expressed as, [19], for which an intrinsic spin polarized is present at B' site, which provides an extra super-exchange contribution in addition to above mentioned two sublattice double exchange contribution. As shown schematically in figure 2(D), in these case, even before switching on the hybridization between B and B' (Cr and Os in the example Figure 2.…”

Section: Magnetism In Double-perovskites-mechanismsmentioning

confidence: 99%

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Double perovskites with 3d and 4d/5d transition metals: compounds with promises

Saha‐Dasgupta

2020

Mater. Res. Express

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Double perovskites, which can host two different transition metal cations at the B-sites of its perovskite derived structure, provide the possibility to explore the interplay of localized 3d transition metals and the relatively delocalized 4d or 5d transition metals within the same structure. This interplay gives rise to extraordinary magnetic properties. In this overview article, we summarize our recent computational efforts in understanding the curious properties of magnetic double perovskites with 3d and 4d/5d transition metal ions, make predictions on new functionalities in known compounds of this family, engineering functionalities via chemical modifications/doping and prediction on a new set of magnetic 3d-4d/5d double perovkite compounds, which may be synthesized to explore and expand further this interesting family.

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Section: A S a S A S A S A Am Mu Anmentioning

confidence: 97%

Section: Magnetism In Double-perovskites-mechanismsmentioning

confidence: 99%

Double perovskites with 3d and 4d/5d transition metals: compounds with promises

Saha‐Dasgupta

2020

Mater. Res. Express

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“…A volume of literature exists on calculated U values of TMs, [22][23][24][25] which suggest the U values of Cr, Mn and Fe atoms in oxides to be 4-5 eV. The U value of a given TM atom, though depends on the environment, i.e., the particular compound under consideration.…”

Section: Predicted Crystal Structuresmentioning

confidence: 99%

Computer predictions on Rh-based double perovskites with unusual electronic and magnetic properties

et al. 2018

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In search for new magnetic materials, we make computer prediction of structural, electronic and magnetic properties of yet-to-be synthesized Rh-based double perovskite compounds, Sr(Ca) 2 BRhO 6 (B=Cr, Mn, Fe). We use combination of evolutionary algorithm, density functional theory, and statistical-mechanical tool for this purpose. We find that the unusual valence of Rh 5+ may be stabilized in these compounds through formation of oxygen ligand hole. Interestingly, while the Cr-Rh and Mn-Rh compounds are predicted to be ferromagnetic half-metals, the Fe-Rh compounds are found to be rare examples of antiferromagnetic and metallic transition-metal oxide with three-dimensional electronic structure. The computed magnetic transition temperatures of the predicted compounds, obtained from finite temperature Monte Carlo study of the first principles-derived model Hamiltonian, are found to be reasonably high. The prediction of favorable growth condition of the compounds, reported in our study, obtained through extensive thermodynamic analysis should be useful for future synthesize of this interesting class of materials with intriguing properties.

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“…All the members of this series are ferromagnetic insulators with a wide range of Curie temperatures from 80 to 280 K. The ferromagnetic insulating nature for these is also predicted through density functional theory calculations. When A is a divalent element, B/B ′ belong to 3d and 4d/5d groups, respectively, the compounds show ferrimagnetism with a Curie temperature above 300 K, and also a large magnetoresistance [17,18,19]. When B ′ is a non-magnetic p-element (e.g.…”

Section: Introductionmentioning

confidence: 99%

Origins of multi-sublattice magnetism and superexchange interactions in double-double perovskite CaMnCrSbO6

Dhawan¹,

Balasubramanian²,

Nautiyal³

2022

Preprint

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Bulk magnetization and neutron diffraction studies on a recently reported double-double perovskite compound CaMnCrSbO 6 (space group : P 4 2 n) suggest ferrimagnetic order (T C ∼49 K), with opposite alignment of Mn 2+ and Cr 3+ spins. The unit cell comprises of two different Mn atoms, denoted as Mn(1) and Mn(2) which have tetrahedral and planar coordination of oxygen atoms, respectively, while the Cr atom is in the centre of orthorhombically distorted octahedron. We have deployed density functional theory, Wannier function analysis, and mean-field calculations to investigate this compound. We find that the super-exchange strengths obtained from DFT are an order of magnitude smaller than those reported for the similar magnetic perovskite and doubleperovskite compounds. The nearest neighbour (along c-direction) Mn(1)-O-Mn(2) superexchange interactions are found to be anti-ferromagnetic and smaller compared to the next nearest neighbour Cr-O-O-Cr super-superexchange interactions, which are found to be ferromagnetic. The in-plane Mn(1)-O-Mn(2) superexchange, also antiferromagnetic, is much smaller due to greater separation between the Mn atoms. The Mn(1)-O-Cr and Mn(2)-O-Cr superexchange interactions are found to be antiferromagnetic. The signs of exchange interactions from DFT predict that while the Cr 3+ spins can be arranged ferromagnetically, the alternate Mn 2+ spins have to be arranged antiferromagnetically. Due to difference in ligand symmetry, the Mn(2)-O-Cr superexchange is weaker than the Mn(1)-O-Cr superexchange, thus effectively resulting in ferrimagnetism, as observed experimentally too. The underlying superexchange mechanisms have been analysed in terms of the hopping integrals between the Wannier orbitals of the transition metal ions and oxygen. Our mean field calculations reveal that assuming a set of four magnetic sub-lattice for Mn 2+ spins and a single magnetic lattice for Cr 3+ spins yields a much improved T C , unlike the use of the two magnetic sublattice model which yields a much higher T C . ‡ Both the authors have made equal contribution.

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Magnetism inSr2CrMoO6: A combinedab initioand model study

Cited by 28 publications

References 58 publications

Double perovskites with 3d and 4d/5d transition metals: compounds with promises

Double perovskites with 3d and 4d/5d transition metals: compounds with promises

Computer predictions on Rh-based double perovskites with unusual electronic and magnetic properties

Origins of multi-sublattice magnetism and superexchange interactions in double-double perovskite CaMnCrSbO6

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