Composition-tunable magnetic properties of {Gd, Dy, Ho}6FeTe2, Ho6RuSb2 ternary compounds and Dy6FeSbBi, Dy6FeSbTe and Dy6FeBiTe quasiternary solid solutions

Abstract

The magnetic ordering and magnetocaloric effect of polycrystalline Fe2P-type Gd6FeTe2, Dy6FeTe2, Ho6FeTe2 and Ho6RuSb2 ternary compounds and Dy6FeSbBi, Dy6FeSbTe and Dy6FeBiTe quasiternary solid solutions (space group P-62m, N 189, hP9) have been investigated using magnetic and heat capacity measurements. Gd6FeTe2 exhibits ferromagnetic ordering with Curie temperature (TC) of 212 K and magnetic entropy change of −4.9 J/kg⋅K in a field change of 50 kOe. Meanwhile, Dy6FeTe2, Ho6RuSb2, Dy6FeSbBi, Dy6FeSbTe and Dy6FeBiTe show high-temperature ferromagnetic ordering (TC) and low-temperature transformation of magnetic ordering (Tm), presenting a table-like magnetocaloric effect in a temperature range from TC to Tm and hard magnet properties at low temperatures. In field of 100 Oe, Ho6FeTe2 exhibits high-temperature antiferromagnetic ordering at TN = 26 K and low-temperature ferromagnetic transition at TC = 6 K with metamagnetic transformation in field lower than 10 kOe. It shows magnetocaloric effect with entropy change of −12.9 J/kg⋅K and −6.2 J/kg⋅K and magnetic enthalpy change of 580 J/kg and 62 J/kg at 22 K and 7 K, respectively, in a field change of 50 kOe.Tuning the magnetocaloric effect and the magnetic ordering via chemical composition is validated in the quasiternary Dy6FeSbBi, Dy6FeSbTe and Dy6FeBiTe solid solutions.