MAGNETIC-SUSCEPTIBILITIES OF UO2-THO2-ZRO2 SOLID-SOLUTIONS

Magnetic susceptibilities were measured from 2. 2 K to room temperature for solid solutions of UO//2-ThO//2-ZrO//2 of which the lattice parameters are the same as that of UO//2, i. e. , Th//0//. //7//yZr//0//. //3//yU//1// minus //yO//2 solid solutions. The Neel temperature decreases linearly with decreasing uranium concentration, the critical concentration being 69 mole% UO//2. The Neel temperatures of the present solid solutions are nearly in the middle of UO//2-ThO//2 solid solutions and UO//2-ZrO//2 solid solutions, which indicates that the magnetic dilution effect of ZrO//2 is larger than that of ThO//2. The effective magnetic moment decreases with decreasing uranium concentration, which is due to a decrease in the magnetic interactions with adjacent uranium concentration, which is due to a decrease in the magnetic interactions with adjacent uranium ions, not due to a change of the strength of crystalline field. The Weiss constant decreases almost linearly with decreasing uranium concentration.