Anisotropic exchange interaction between nonmagnetic europium cations in Eu2O3

The electronic structure of the cubic and (high pressure) hexagonal phases of Eu2O3 have been investigated by mean of full potential linearized augmented plane wave calculations, within the LDA+U method. For the cubic phase, the comparison between ferromagnetic and antiferromagnetic calculations shows that the exchange interaction is very weak and is therefore expected to have a negligible effect on the magnetic susceptibility. This is consistent with the experimental behavior of the susceptibility of solid solutions of Eu2O3 into A2O3 (A=Y, Lu, Sc). The calculations performed for the high pressure hexagonal phase, on the other hand, show that there is an antiferromagnetic exchange interaction between nearest neighbor Eu ions, which should have a sizeable effect on the susceptibility. Our results allow us to discuss the existing theories.

[1]  R. M. Moon,et al.  Magnetic Structures ofEr2O3andYb2O3 , 1968 .

[2]  J. Szade,et al.  Electronic structure and photoemission properties of EuF3 and EuCo2X2 (X = Si, Ge) compounds by ab initio methods , 2007 .

[3]  A. Prokofiev,et al.  Periodicity in the band gap variation of Ln2X3 (X = O, S, Se) in the lanthanide series , 1996 .

[4]  O. Malta,et al.  The crystal field strength parameter and the maximum splitting of the 7F1 manifold of the Eu3+ ion in oxides , 1995 .

[5]  R. L. Weber,et al.  The Physical Principles of Magnetism , 1967 .

[6]  G. Blasse,et al.  Energy transfer between Eu3+ ions in a lattice with two different crystallographic sites: Y2O3:Eu3+, Gd2O3:Eu3+ and Eu2O3 , 1987 .

[7]  E. Zych,et al.  Concentration dependence of energy transfer between Eu3+ ions occupying two symmetry sites in Lu2O3 , 2002 .

[8]  J. Kunes R. Laskowski.  Magnetic ground state and Fermi surface of bcc Eu , 2004 .

[9]  M. Mitrić,et al.  Cation ordering in cubic and monoclinic : an x-ray powder diffraction and magnetic susceptibility study , 1997 .

[10]  B. Johansson,et al.  Theoretical investigation of the isomer shift of InSb under pressure , 2002 .

[11]  P. Caro,et al.  The paramagnetic susceptibility of C-type europium sesquioxide , 1986 .

[12]  J. V. Vleck,et al.  Effect of the Anisotropic Exchange and the Crystalline Field on the Magnetic Susceptibility of Eu2O3 , 1969 .

[13]  A. Grill,et al.  MAGNETIC SUSCEPTIBILITIES OF CUBIC MIXED EUROPIUM OXIDES. , 1970 .

[14]  I. I. Mazin,et al.  Correlated metals and the LDA+U method , 2002, cond-mat/0206548.

[15]  Z. Szotek,et al.  First principles study of rare-earth oxides , 2005, cond-mat/0503667.

[16]  F. Birch,et al.  Finite strain isotherm and velocities for single‐crystal and polycrystalline NaCl at high pressures and 300°K , 1978 .

[17]  W. Pickett,et al.  Magnetic coupling between nonmagnetic ions: Eu 3+ in EuN and EuP , 2005, cond-mat/0508241.

[18]  H. Lal,et al.  Electrical conduction in non-metallic rare-earth solids , 1988 .

[19]  S. Kern,et al.  Magnetic Susceptibility of Eu2O3 , 1971 .

[20]  J. B. Gruber,et al.  SPECTRA AND ENERGY LEVELS OF EU(3+) IN Y2O3. , 1964 .

[21]  K. Bagdasarov,et al.  Real structure of undoped Y2O3 single crystals , 1984 .