Münster 1999 – scientific programme
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TT: Tiefe Temperaturen
TT 7: Heavy Fermions
TT 7.2: Talk
Tuesday, March 23, 1999, 10:00–10:15, F1
Heavy fermion formation and magnetic interactions in LiV2O4 — •V. Eyert1,2, K.-H. H"ock2, S. Horn2, A. Loidl2, and P. S. Riseborough3 — 1Hahn-Meitner-Institut, D-14109 Berlin — 2Institut f"ur Physik, Universit"at Augsburg, D-86135 Augsburg — 3Physics Dept., Polytechnic University, New York, N.Y. 11201
We present results of all-electron electronic structure calculations for the recently discovered d electron heavy fermion compound LiV2O4 . The augmented spherical wave calculations are based on density functional theory within the local density approximation. The electronic properties are dominated by O 2p and crystal field split V 3d orbitals. Electronic bands near the Fermi energy originate almost exclusively from V 3d t2g states. Allowing for spin polarization we arrive at a, however geometrically frustrated, antiferromagnetic ground state and an additional ferromagnetic solution. On varying the V – O bondangle we find drastic changes almost exclusively of the narrow local V 3d3z2−r2 ( a1g ) states pointing along the ⟨111⟩ direction, which split off from the t2g states due to the small trigonal component of the crystal field, while the remaining, rather broad egπ states are essentially unaffected. In the spin-polarized calculations, this leads to a change of the local magnetic moments as well as a crossover from antiferro- to ferromagnetic order.