MAGNETIC AND ELECTRICAL BEHAVIORS OF SR8V8O25

The DC magnetization M, AC magnetic susceptibility chi' and chi '', an d electrical resistivity rho were measured for Sr8V8O25 polycrystals. The magnetic susceptibility showed ferrimagnetic temperature dependenc e, and the transition temperature T-C was estimated as 105 K. Below T- C, the steep increase of magnetic susceptibility and the ferrimagnetic M-H curves were observed. The peaks of chi' and chi '', and the visib le splitting of the field cooled magnetization (FCM) and zero field co oled magnetization (ZFCM) appeared at T-p = 57 K. These behaviors show the rapid increase of magnetic relaxation time below T-p. The existen ce of a major M-H loop with a large coercive force was assumed at 5 K from the positively shifted FCM-H loop and small ZFCM, which also supp orted the above interpretation. The temperature dependence of rho was semiconductive above T-p with a slight change of activation energy nea r T-C, while the hopping conductive behavior and the current dependenc e of rho appeared below T-p. The existence of thermal hysteresis in rh o below T-p suggested that the magnetic and electrical anomalies at T- p were induced by the structural phase transition of Sr8V8O25.