Magnetic properties of three pseudobinary RCo5 alloy systems

The field dependence of the magnetization was measured in the magnetically easy and hard directions as a function of composition and temperature in the pseudobinary systems Pr/sub x-/ Sm/sub 1-x/Co5, Y/sub x/Nd/sub 1-x/Co5, and Gd/sub x/Nd/sub 1-x/Co5. The saturation magnetization was determined and the anisotropy constants K1 and K2 were calculated from hard direction magnetization data. It was assumed that the net magnetization and anisotropy of the alloys could be divided into components representing the cobalt-cobalt, rare earth-cobalt, and rare earth-rare earth interactions. Data on YCo5 was employed to account for the effect of the first interaction and the remaining two interactions were separated by means of some simple and physically reasonable assumptions. The resulting rare earth-rare earth magnetization and anisotropy data was then tested to see if it could be described by the single ion model. It was concluded that the single ion model did not describe the rare earth-rare earth interaction well in these alloys. This conclusion is in agreement with published results on light rare earth metals and alloys. It was further observed that some of the characteristics of the rare earth-rare earth interaction could be accounted for by assuming the existence of a band-type interaction between the rare earth atoms. All the alloys which contained Nd were found to exhibit low-temperature magnetization anomalies which were thought to be due to the existence of relatively strong basal plane anisotropy in these alloys