Sputtered Sm-Co films: Microstructure and magnetic properties

Films of Sm-Co have been sputtered on heated polycrystalline Al2O3 substrat es. The effect of variations of the Sm content on microstructure and hard m agnetic properties was studied for otherwise constant process parameters. A s generally observed, the samples possess a magnetic texture where the easy magnetization directions of the grains lay preferably in the film plane. F or a lower Sm content the TbCu7-type structure is stabilized and for a high er Sm content the CaCu5-type structure is stabilized. The crossover occurs for a Sm content of around 17 at. %. Consistent with the changes in the int rinsic properties, coercivity increases and remanence decreases with increa sing the Sm content. The grain size increases with increasing the Sm conten t and is attributed to a higher surface mobility during crystallization and grain growth. This behavior is also assumed to cause the improvement in th e in-plane texture with increasing the Sm content, that had been quantified by magnetic and crystallographic investigations. (C) 1999 American Institu te of Physics. [S0021-8979(99)07520-9].