ELECTRONIC STATES OF VANADIUM SPINELS MGV2O4 AND ZNV2O4

Electronic states of the normal vanadium spinels MV(2)O(4) (M=Mg and Zn) and the Mg(V1-xAlx)(2)O-4 system have been studied through the measurements of X-ray diffraction, electrical resistivity, magnetic susceptibility and NMR of the V-51 and Al-27 nuclei. Apparently large Curie constants and Weiss temperatures in MV(2)O(4) have been found to be attributed to the spin frustration on the characteristic network of V ions. It has also been indicated that a substitution of V ions by nonmagnetic Al ions leads to the phase similar to spin glass at low temperatures, and stabilizes the short-range ordered spin clusters at high temperatures.