Pulsed laser deposited epitaxial Sm–Co thin films with uniaxial magnetic texture

Abstract

Sm–Co thin films have been grown epitaxially with pulsed laser deposition on Cr buffered MgO(110) substrates. The buffer microstructure plays a significant role in controlling the growth and hence the magnetic properties of the Sm–Co film. High deposition temperatures of the Cr buffer result in a rough and discontinuous microstructure, thereby resulting in an x-ray amorphous or nanocrystalline Sm–Co layer, as has been confirmed by transmission electron microscopy studies. By lowering the buffer deposition temperature from 700to300°C, the roughness decreases from 5to0.6nm. Sm–Co films grow epitaxially on these low temperature buffers with the epitaxial relation MgO(110)[001]∥Cr(211)011∥SmCo(100)[001] which implies a single in-plane orientation of the c axis along the MgO[001] direction. The strong in-plane crystallographic texture seen in the pole figure measurements leads to a very pronounced magnetic texture, quantified by a remanence ratio JrMgO[110]∕JrMgO[001] as low as 0.08 and a high remanence of 0.84T along with a high coercivity of 3T when measured along the easy axis.