Dresden 2003 – wissenschaftliches Programm

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MA: Magnetismus

MA 26: Elektronentheorie

MA 26.10: Vortrag

Donnerstag, 27. März 2003, 17:30–17:45, HSZ/401

Anisotropic Bonding and Unconventional Metallic Magnetism in LaCrSb₃ — •Manuel Richter¹, Jan Rusz², Helge Rosner³, Klaus Koepernik¹, Ingo Opahle¹, Ulrike Nitzsche¹, and Helmut Eschrig¹ — ¹IFW Dresden, PF 270 116, D-01171 Dresden — ²Department of Electronic Structures, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2 — ³MPI Chemical Physics of Solids, Nöthnitzer Str. 40, D-01187 Dresden

The intermetallic compound LaCrSb₃ is a noncollinear ferromagnet with an ordered moment of about 1.9 µ_B at Cr, oriented in the b-direction of the orthorhombic structure with alternating tilting. The spin structure flips, without changing its internal arrangement, into the c-direction at T_sr= 95 K. Such a spin reorientation is usually a sign of competing magnetic interactions. In the present case, it was discussed as indication for coexistance of localized and itinerant spins due to the highly anisotropic crystal structure of LaCrSb₃ that may lead to different degrees of hybridization of the Cr 3d orbitals [1].

We confirm this point of view by electronic structure calculations in the local spin density approximation. While the fully polarized 3d-states with |m_l|=1 show almost no dispersion, the other 3d-states can be identified as itinerant, weakly polarized states. Assuming collinear order, we find a moment about 10% larger than the experimental moment. The calculations were carried out with the WIEN2k and FPLO-2 methods.

[1] E. Granado et al., Phys. Rev. Lett. 89 (2002) 107204.