Sputtered Sm–Co films: Microstructure and magnetic properties

Abstract

Films of Sm–Co have been sputtered on heated polycrystalline Al2O3 substrates. The effect of variations of the Sm content on microstructure and hard magnetic properties was studied for otherwise constant process parameters. As generally observed, the samples possess a magnetic texture where the easy magnetization directions of the grains lay preferably in the film plane. For a lower Sm content the TbCu7-type structure is stabilized and for a higher 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 intrinsic properties, coercivity increases and remanence decreases with increasing the Sm content. The grain size increases with increasing the Sm content and is attributed to a higher surface mobility during crystallization and grain growth. This behavior is also assumed to cause the improvement in the in-plane texture with increasing the Sm content, that had been quantified by magnetic and crystallographic investigations.

Magnetic properties of Sm-Co thin films grown on MgO(100) deposited from a single alloy target

“…Due to the thickness and high crystallinity, also the K b peak of the MgO substrate is visible. In Figure 1(b), the region around the SmCo (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) peak is shown, for films grown with a sputter pressure of 1.5, 3.0, 7.5, and 10.5 Â 10 À3 mbar. Clearly visible is that, with decreasing pressure, the peaks shift to a higher angle.…”

“…However, for various applications, growing Sm-Co thin films from alloy targets is a desirable option since only one deposition source is needed. Still, as far as we know, relatively few groups [12][13][14][15][16][17][18][19][20] have reported on the growth of Sm-Co thin films from single alloy targets. The purpose of this work is to show what the properties are of such films, grown on MgO(100), and in a range of pressures.…”

Investigation of cellular microstructure and enhanced coercivity in sputtered Sm2(CoCuFeZr)17 film

“…Though extensive research has been done on the films of Sm-Co binary and ternary alloys, very few results are reported on sputtered thin film of Sm 2 (CoCuFeZr) 17 composition. [17][18][19][20] The studies performed on thin films of this composition are mainly focused on the effect of sputtering parameters such as gas pressure, substrate temperature, sputtering gas, etc., on the magnetic properties. 17,19 The maximum coercivity of $0.4 to 1 T has been reported up to now by Hedge et al for Sm(CoCuFeZr) z thin film sputtered at 350 C. 20 The coercivity is attributed to the texture growth of the film with the crystallite c-axis lying in the film plane.…”

“…[17][18][19][20] The studies performed on thin films of this composition are mainly focused on the effect of sputtering parameters such as gas pressure, substrate temperature, sputtering gas, etc., on the magnetic properties. 17,19 The maximum coercivity of $0.4 to 1 T has been reported up to now by Hedge et al for Sm(CoCuFeZr) z thin film sputtered at 350 C. 20 The coercivity is attributed to the texture growth of the film with the crystallite c-axis lying in the film plane. However, to the best of our knowledge, no single study has been reported so far on the development of cellular microstructure growth in Sm(CoCuFeZr) z films.…”

Deposition of hard magnetic SmCo5thin films by magnetron sputtering

“…One of the major requirements of such applications is the need to deposit permanent magnetic films with high coercivity and large energy products on silicon substrates. Among the rare earth group of permanent magnetic films SmCo films offer excellent intrinsic and extrinsic magnetic properties [3][4][5][6].…”