Different target configurations have been used to directly synthesize Sm-Co based films by selectively thermalized rf sputtering onto heated substrates in an in-plane magnetic field. Samples have been sputtered so that in certain cases a systematic gradient in Sm-to-Co concentration was created along the length of the substrates and in other cases so that films of a fixed uniform composition were deposited. Small subregions of a single substrate then serve as samples of a specific composition. For the Sm-to-Co composition range from 70 to 95 at. % Co gradient synthesized samples exhibit high magnetization and moderate intrinsic coercive forces. The maximum energy product of 20 MG Oe was obtained for a sample with 90.6 at. % Co containing mostly the Sm2Co17 phase. In addition, samples were synthesized from uniform composition targets at certain fixed compositions. Films sputtered from uniform composition Sm2(Co, Fe, Zr)17 targets exhibited square in-plane hysteresis loops and static energy products up to 21.2 MG Oe. It was observed that uniform composition SmCo5 films could be grown which exhibited either the (200) or the (110) texture as a function of the sputtering rate. Relatively higher sputtering rates of approximately 5 Å/sec resulted in the (200) texture growth pattern while lower rates resulted in (110) textured films. These differently textured SmCo5 films differ in both their microstructure and magnetic properties. The (110) textured film are finer in microstructure and magnetically harder than the (200) films. The uniform composition SmCo5 films of either texture in general were of smaller grain size and higher coercive forces than the SmCo5 subregions from films sputtered with a composition gradient spanning the 1–5 phase. A uniform composition SmCo5 film sputtered at 1.5 Å/sec which was (110) textured exhibited an intrinsic coercive force of 23 kOe and an energy product of 18 MG Oe at −63 °C. The high-energy products reported here are due to both the high induction and to the squareness of the in-plane hysteresis loops when measured in the direction parallel to the field applied during the sputter synthesis.

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Samples of the Sm-Fe system have been directly crystallized onto heated substrates by selectively thermalized sputtering. Films of the pure Sm-Fe system exhibit only the 1-2, 1-3, and 2-17 phases which correspond to the bulk system. But samples synthesized with certain third element additions of oxygen and titanium exhibit a metastable phase at a composition corresponding to a 1-5 Sm-Fe compound. These samples exhibit well defined and reasonable sharp x-ray diffraction patterns. Room-temperature intrinsic coercive forces of6.2 kOe and static energy products of5.5 MG Oe have been observed. These results are for the demagnetizing field in the plane of the thin film samples and no demagnetizing factor has been used in obtaining the inplane B field. Samples synthesized in the presence of an inplane magnetic field at 600 ·C exhibit an inplane anisotropy which indicates the Curie point of this Ti-stabilized SmFe 5 phase should be greater than 600 DC. Film samples of the pure Sm-Fe system which do not show a metastable phase generally have low intrinsic coercive forces and consequently low energy products. PACS numbers: 75.60. -d, 75.50. -y, 8U5.Cd FIG. 5. X-ray diffraction of Ti-stabilized SmFe, phase of Fig. I sample, CuK" radiation in reflection.Cadieu eta/. 2612 J ~ + 0 [This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to ] IP: 155.33.16.124 On: Thu

Ferromagnetic films of the Sm–Co and Sm–Fe systems have been synthesized by sputtering onto substrates at temperatures above 600 °C so that the deposit is directly crystallized upon deposition. For the directly synthesized phases, high sputtering gas pressures were used so that the sputtered atoms transferred excess momentum to the sputtering gas atoms before arriving at the substrate. The object has been to promote the growth of possible metastable phases and to allow preferred orientation effects to be present in the films. Directly synthesized SmCo5 films grown by this method, showed a predominant (110) texture, for oxygen levels in the films of greater than about 6 at. %. As the oxygen incorporation level in the SmCo5 films was reduced to 1.4 at. % oxygen, only a (200) texture was observed. In Sm–Fe films with 6.5 at. % oxygen, a new metastable phase forms at the 1–5 composition. This oxygen stabilized metastable phase is not present in Sm–Fe films made with lower amounts of oxygen incorporation.