Magnetic susceptibility and effective magnetic moment of the Nd and Co ions in NdCo1 - x Ga x O3

The magnetic susceptibility of NdCo1 - x Ga x O3 (x = ,0.,0.,0.,0.,0.8, 0.9, 1) has been measured at temperatures from 80 to 950 K. The effective magnetic moments (mueff) due to the magnetic moments of the Co and Nd ions have been determined in the temperature ranges of Curie-Weiss behavior, 130-370 and 600-940 K, and have then been used, together with the effective magnetic moment of Nd (3.62muB or 4.20muB), to evaluate the effective magnetic moment of Co in NdCo1 - x Ga x O3. For the solid solutions with {expression} < 2.83muB, we have determined the fractions of intermediate-and low-spin Co ions. In the range 2.83muB < {expression} < 4.90muB, we have determined the fraction of high-spin Co ions. The results indicate that, in the temperature range 130-370 K, the Co ions in NdCo1 - x Ga x O3 with x = ,0.,0.8, and 0.9 are in the intermediate-and high-spin states, and the fraction of high-spin Co ions gradually increases from 10% at x = 0 to 67% at x = 0.9. In the solid solutions with x = 0.,0.,0.3, and 0.7, more than half of the Co ions are in the low-spin state, and the rest are in the intermediate-spin state. In the temperature range 600-940 K, the Nd ions are in the ground and excited states, with theoretically predicted of {expression} of 3.62muB and 5.52muB, respectively. Because of the significant uncertainty in {expression} in this temperature range, {expression} has been determined less accurately compared to the range 130-370 K.