TY - JOUR

T1 - First-principles prediction of spin-density-reflection symmetry driven magnetic transition of CsCl-type FeSe

AU - Rahman, Gul

AU - Gee Kim, In

AU - Freeman, Arthur J.

N1 - Funding Information:
The authors appreciate H.K.D.H. Bhadeshia for his careful reading of the manuscript. I.G. Kim thanks Jong-Hoon Chung for helpful discussions on experimental realization. This work was supported in part by the Steel Innovation Program of POSCO, by the Basic Science Research Program (Grant no. 2009-0088216 ) through the National Research Foundation funded by Ministry of Education, Science and Technology of the Republic of Korea, and by the US Department of Energy (Grant no. DE-FGO2-88ER 45372 ).

PY - 2010/10

Y1 - 2010/10

N2 - Based on results of density functional theory (DFT) calculations with the local spin density approximation (LSDA) and the generalized gradient approximation (GGA), we propose a new magnetic material, CsCl-type FeSe. The calculations reveal the existence of ferromagnetic (FM) and antiferromagnetic (AFM) states over a wide range of lattice constants. At 3.12 in the GGA, the equilibrium state is found to be AFM with a local Fe magnetic moment of ±2.69μB. A metastable FM state with Fe and Se local magnetic moments of 2.00 and -0.032μB, respectively, lies 171.7 meV above the AFM state. Its equilibrium lattice constant is ∼2% smaller than that of the AFM state, implying that when the system undergoes a phase transition from the AFM state to the FM one, the transition is accompanied by volume contraction. Such an AFMFM transition is attributed to spin-density z-reflection symmetry; the symmetry driven AFMFM transition is not altered by spinorbit coupling. The relative stability of different magnetic phases is discussed in terms of the local density of states. We find that CsCl-type FeSe is mechanically stable, but the magnetic states are expected to be brittle.

AB - Based on results of density functional theory (DFT) calculations with the local spin density approximation (LSDA) and the generalized gradient approximation (GGA), we propose a new magnetic material, CsCl-type FeSe. The calculations reveal the existence of ferromagnetic (FM) and antiferromagnetic (AFM) states over a wide range of lattice constants. At 3.12 in the GGA, the equilibrium state is found to be AFM with a local Fe magnetic moment of ±2.69μB. A metastable FM state with Fe and Se local magnetic moments of 2.00 and -0.032μB, respectively, lies 171.7 meV above the AFM state. Its equilibrium lattice constant is ∼2% smaller than that of the AFM state, implying that when the system undergoes a phase transition from the AFM state to the FM one, the transition is accompanied by volume contraction. Such an AFMFM transition is attributed to spin-density z-reflection symmetry; the symmetry driven AFMFM transition is not altered by spinorbit coupling. The relative stability of different magnetic phases is discussed in terms of the local density of states. We find that CsCl-type FeSe is mechanically stable, but the magnetic states are expected to be brittle.

KW - CsCl-type FeSe

KW - Electronic structure

KW - First-order magnetic transition

KW - First-principles calculations

KW - Mechanical stability

KW - Spin-density-reflection symmetry

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U2 - 10.1016/j.jmmm.2010.05.051

DO - 10.1016/j.jmmm.2010.05.051

M3 - Article

AN - SCOPUS:77955308034

SN - 0304-8853

VL - 322

SP - 3153

EP - 3158

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

IS - 20

ER -