Texture and Microstructure Studies on Films of Ni-Mn-Ga Produced by R. F. Sputtering and Pulsed Laser Deposition

Introduction Ni-Mn-Ga films were grown on (110) MgO substrates by r.f. sputtering and pulsed laser deposition techniques. Texture analyses, in combination with electron microscopy measurements, reveal that the films from the two deposition techniques both have a cubic L21 structure, but differ in terms of their texture and grain morphology. The sputtered films grow along the <110> direction with completely random in-plane orientation. The PLD films, on the other hand, grow in the <422> direction such that there exists two distinct grain-types, where both types share an epitaxial relationship with the substrate. In general, the overall quality of the PLD films is better than the sputtered films. The growth conditions that influence film morphology and texture are discussed.