Magnetisation and magnetoresistance of YMn 6Sn 6− xIn x compounds ( x=0.10, 0.18, 0.21, 0.38)

Abstract

Polycrystalline samples of HfFe 6Ge 6-type YMn 6Sn 6− x In x compounds (0.10≤ x≤0.38) have been studied by X-ray diffraction, high field magnetisation and magnetoresistance measurements. The low In content compounds order antiferromagnetically ( T N=328, 321 and 309 K for x=0.10, 0.18 and 0.21, respectively) while YMn 6Sn 5.62In 0.38 orders ferromagnetically ( T c=329 K) and undergoes a ferro- to antiferromagnetic transition on cooling ( T t=240 K). All compounds display metamagnetic behaviour at 10 K associated with giant magnetoresistance (Δ R/ R∼−30% for x=0.10). The different magnetoresistance effects measured in the x=0.18 and 0.21 compound seems to be related to different textures suggesting a more pronounced magnetoresistance along the [001] direction. Results are discussed and compared with properties of isotypic series.