Spin glass and metallic antiferromagnetism in disordered (Ti1−xVx)2O3: High magnetic field and x-ray studies

(Ti1−xVx)2O3 has been shown to be a spin glass for 0.5%<x<10% and a micromagnet at higher V concentrations. For x≳0.4, magnetic susceptibility and electrical resistivity data give experimental evidence for a metallic antiferromagnetic phase, with Neel temperatures ranging from 60 K to 10 K, depending on x. Magnetization measurements have been performed for several V concentrations, at 4.2 K and 1.4 K in fields up to 150 kG. For 0.01<x<0.10, the approach to saturation can be discussed in terms of the Virial theory of Larkin et al.; the strength V0 of the RKKY interaction is found of the order of 0.5×10−36 erg cm3 and of the same order of magnitude as the value deduced from the initial reversible susceptibility extrapolated to T=0 K. For x=0.2% the large value of V0, compared with the transport properties, which are well described at low temperatures by a hopping process of the electrons, suggest that such a hopping mechanism might be responsible for efficient magnetic couplings between the V ions. For x=0.75, the absence of any saturation of the magnetization at 4.2 K up to 150 kG corroborates the antiferromagnetic nature of this compound. X-ray studies also show lattice parameter and volume anomalies (?0.2%) below the Neel temperature.