Pb cation induced low-temperature crystallization of (Ba•Pb) hexa-ferrite thin films

We have studied the low-temperature crystallization of (Ba (.) Pb) hexa-ferrite thin films using real time synchrotron X-ray scattering, anomalous X- ray scattering, and vibrating sample magnetometer. The crystallization temperature of amorphous (Ba (,) Pb) hexa-ferrite film (300-angstrom- thick, similar to 530 degrees C) was much lower than that of amorphous Ba hexa-ferrite film, similar to 750 degrees C. The crystalline ( Ba (.) Pb) hexaferrite phase was formed by solid phase transformation of the interfacial crystalline Fe3O4 phase through the diffusion of Ba or Pb cations. The low crystallization temperature of the (Ba (.) Pb) hexa-ferrite phase was due to the lower diffusion activation barrier of Pb cations than that of Ba cations. The small grain size (similar to 40 nm in diamter) and comparable magnetic properties (Ms-perpendicular to: 337 emu/cm(3), iHc(perpendicular to) : 1.60 kOe) of the crystallized (Ba (.) Pb) hexa-ferrite film also demonstrate its potential possibility for high-density recording media.