MAGNETIZATION AND THERMOREMANENT MAGNETIZATION OF TB2MO2O7 AND Y2MO2O7 SPIN-GLASSES

Tb2Mo2O7 and Y2Mo2O7 are crystalline oxides having the pyrochlore structure. Magnetic susceptibility measurements have shown a magnetic transition which is similar to a spin glass below 27 and 22 K for Tb2Mo2O7 and Y2Mo2O7 respectively. Experimental measurements of the low field susceptibility, the magnetic hysteresis loop, the thermoremanent magnetization (TRM) and the time decay of the remanent magnetization have been carried out. A shift from the origin in the magnetic hysteresis loop, the disappearance of TRM at the transition temperature and a logt decay of the remanent magnetization have been observed. All these experimental observations strongly suggest a spin glass behavior for Tb2Mo2O7 and Y2Mo2O7 below 27 and 22 K respectively.