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

Abstract

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-Å-thick, ∼530 • C) was much lower than that of amorphous Ba hexa-ferrite film, ∼750 • C. The crystalline (Ba·Pb) hexaferrite phase was formed by solid phase transformation of the interfacial crystalline Fe 3 O 4 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 (∼40 nm in diamter) and comparable magnetic properties (Ms ⊥ : 337 emu/cm 3 , iHc ⊥ : 1.60 kOe) of the crystallized (Ba·Pb) hexa-ferrite film also demonstrate its potential possibility for high-density recording media.

Lead Hexaferrite - A Brief Review

“…(Ba•Pb) hexaferrite films were grown on sapphire (00l) by rf magnetron sputtering. [64]. Due to the lower diffusion activation barrier of Pb cations than that of Ba, crystallization at low temperature, 530 ºC, was achieved.…”