Low-temperature coercivity of Mo2NiB2-type Tb2Co2Ga and Tb2Co2Al-based solid solutions

• Published in: Journal of solid state chemistry 2019-09, Vol.277, p.406-414
• Main Authors: Morozkin, A.V., Yao, Jinlei, Knotko, A.V., Yapaskurt, V.O.
• Format: Article
• Language: English
• Subjects: Crystal structure; Magnetic properties; Magnetocaloric effect; Permanent magnet; Rare-earth compounds
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2019.06.041

The magnetic ordering of polycrystalline Mo2NiB2-type Tb2Co2Ga and Tb2Co2Al-based Sm2-xTbxCo2Al, Tb2Co2Al1-xGax and Tb2Co1.8{Ni, Cu}0.2Al solid solutions has been established using bulk magnetic measurements. These compounds undergo a high-temperature ferromagnetic ordering and field sensitive transformation of magnetic ordering at low temperatures. The high-temperature ferromagnetic ordering is followed via negative magnetic entropy change and soft magnet properties, whereas low-temperature transformation of magnetic ordering indicates positive magnetic entropy change and excellent permanent magnet properties. The magnetic ordering of polycrystalline Mo2NiB2-type Tb2Co2Ga and Tb2Co2Al-based Sm2-xTbxCo2Al, Tb2Co2Al1-xGax and Tb2Co1.8{Ni, Cu}0.2Al solid solutions has been established using bulk magnetic measurements. These compounds undergo a high-temperature ferromagnetic ordering and field sensitive transformation of magnetic ordering at low temperatures. The high-temperature ferromagnetic ordering is followed via negative magnetic entropy change and soft magnet properties, whereas low-temperature transformation of magnetic ordering indicates positive magnetic entropy change and excellent permanent magnet properties. [Display omitted] •Tb2Co2Ga and Tb2Co2Al-based solutions show high-temperature ferromagnetic ordering.•This HT ferromagnetic ordering corresponds to the negative ΔSm and soft magnet properties.•They exhibits low-temperature field sensitive transformation of magnetic ordering.•This LT transformation is followed positive ΔSm and permanent magnet properties.•Tb2Co2Ga is giant permanent magnet with Hcoer of 48 kOe and (BH)max of 1068 kJ/m3 at 2 K.