Giant low-temperature magnetostriction and spin-reorientation of polycrystalline alloy PrFe1.9

摘要

A remarkably giant intrinsic magnetostriction λ111 as high as 6700?ppm was found at 70?K in PrFe1.9 compound, which is much larger than the value of 5600?ppm predicted by single-ion theory. Change of the easy magnetization direction from [111] to [100] with decreasing temperature occurs between 30 and 70?K, which was verified by step-scanned {440} and {222} X-ray diffraction reflections. It was further demonstrated that this compound has a rhombohedral symmetry between 70 and 300?K, and a tetragonal symmetry between 15 and 30?K. Therefore, the magnetostrictive anomaly at low temperature may be interpreted by the spin reorientation transition of the compound. PrFe1.9 with high magnetostriction is a good candidate material for magnetostriction applications at low temperature.