Functional intermetallic compounds in the samarium–iron system

Abstract

Magnetism of intermetallic compounds SmFe 2 , SmFe 3 , Sm 6 Fe 23 , and SmFe 7 were studied in detail using single crystals and the use of these materials has been discussed. SmFe 2 and Sm 6 Fe 23 have cubic magnetocrystalline anisotropy and the easy axis of magnetization in the [111] direction. SmFe 2 has giant negative magnetostriction that can be used for microactuator or ultrasonic generator. SmFe 3 has a relatively large saturation moment and uniaxial anisotropy, which are promising for application as a perpendicular magnetic recording medium. Large saturation magnetization and extremely large magnetocrystalline anisotropy of SmFe 7 seem promising as an absorber in the frequency range of milliwave as well as a high performance permanent magnet. q

Influence of Boron Addition on Magnetic Properties of Sm2Fe17 Alloy

“…The Curie temperature of the samples increased from 130 • C to 361 • C with the boron addition to the alloy, due to the existence of SmFe 3 phase in the microstructure. The saturation magnetization has the highest value of 155.5 emu/g and decreases to its lowest value of 97.9 emu/g for the sample at x = 4 because Sm 2 Fe 17 has the higher saturation magnetization (117 emu/g) than that of SmFe 3 phase (80.7 emu/g) [5]. In the study, boron addition and heat treatment at 1000 • C resulted in an evolution of the phase constitution that caused changes in magnetic properties of the alloy instead of occupation of boron atoms in the interstitial sites of Sm 2 Fe 17 structure such as C and N.…”

“…With the addition of boron, the saturation magnetization decreased to its lowest value of 97.9 emu/g for the sample at x = 4. This may be due to the decrease in the amount of Fe in the microstructure and also due to the fact that Sm 2 Fe 17 has the higher saturation magnetization (117 emu/g) than that of SmFe 3 phase (80.7 emu/g) [5].…”

TbCu7-type Sm-Fe(-N) powder synthesized by low-temperature reduction-diffusion process using the Li–Ca reductant

“…This phenomenon was investigated in our previous studies [ 21 , 22 ]. Although the amount of ɑ-Fe phase decreased and the ɑ-Fe phase disappeared as the amount of Sm increased, it was found that excessive Sm addition resulted in the formation of a Sm-rich phase, which causes a decrease in saturation magnetization [ 36 ]. Therefore, the Sm ratio that achieves the smallest amount of the ɑ-Fe phase without the formation of the SmFe 3 phase should be selected.…”

From SmOF to SmH0.78OF0.22: H/F Substitution in Oxide Fluorides as a Synthesis Route to Heteroanionic Compounds

“…Magnetic materials are mostly intermetallics like Sm−Fe compounds for magnetic recording and Sm−Co compounds as permanent magnets. 1 SmCo 5 is one of the strongest permanent magnet materials, 2 which outperforms many others for high-temperature applications because of its high Curie temperature, T C , of 1015 K (compare to e.g. Nd 2 Fe 14 B with T C = 600 K).…”

“…Its compounds find widespread application as functional materials due to their magnetic, optic, or nuclear characteristics. Magnetic materials are mostly intermetallics like Sm–Fe compounds for magnetic recording and Sm–Co compounds as permanent magnets . SmCo 5 is one of the strongest permanent magnet materials, which outperforms many others for high-temperature applications because of its high Curie temperature, T C , of 1015 K (compare to e.g.…”