The structural and magnetic properties of films of Pr₂Fe₁₄B and Nd₂Fe₁₄B cosputtered with Ta

The results of structural and magnetic measurements on films, produced by serially depositing R₂Fe₁₄B (R = Nd, Pr) and Ta, are reported. The materials were deposited 10-200 Å at a time onto 500-700°C Ta substrates. The structures of the resulting films were examined by large- and small-angle X-ray diffraction. The magnetic properties were studied at room temperature in a Vibrating Sample Magnetometer (VSM) with a maximum field of 17.1 kOe, and at cryogenic temperatures in a VSM with a maximum field of 80 kOe. The structural and magnetic properties depend upon the nominal thickness of the Ta, even though interlayer diffusion appears to be significant for Ta thickness less than about 30 Å. The trends in the coercivities can be qualitatively explained by assuming a nucleation mechanism for magnetization reversal and correlating the coercivity with the degree of c-axis alignment in the 2:14:1 phase.