Gnezdilov, V.
Lemmens, P.
Zvyagin, A. A.
Cheranovskii, V. O.
Lamonova, K.
Pashkevich, Yu. G.
Kremer, R. K.
Berger, H.
Magnetic crossover and complex excitation spectrum of the ferromagnetic/antiferromagnetic spin1/2 chain system alphaTeVO4
Physical Review B
10.1103/PhysRevB.78.184407
78

We report magneticsusceptibility, specificheat, and Ramanscattering investigations of alphaTeVO4 containing VO edgesharing chains. These chains promote a system of ferromagnetic/antiferromagnetic spin1/2 Heisenberg alternating exchange chains with pronounced spin frustration. The magnetic susceptibility and Raman scattering evidence a crossover at T*=85 K with different slopes of the reciprocal susceptibility and a magnetic phase transition into a longrangeordered state at Tc=16 K. From Ramanscattering data a strong mutual coupling between lattice and magnetic degrees of freedom is deduced. A comparison to model calculations and prior Raman scattering on other chain systems yields a plausible interpretation of the microscopic mechanism for the crossover behavior.
NearestNeighbor Interactions;
LightScattering;
HeisenbergChains;
CrystalStructure;
RamanScattering;
Antiferromagnets;
Fluctuations;
Temperature;
Transition;
Dynamics;
2008