Thermal expansion, specific heat and forced magnetostriction in Y₉Co₇

Abstract

Measurements of thermal expansion, specific heat and forced magnetostriction have been performed on several Y9Co7 samples in order to study magnetism and superconductivity in this compound by means of the magnetovolume relation. An analysis of the zero-field thermal expansion and the forced magnetostriction data is hampered by large sample-dependent magnetic shape effects. The excess specific heat in the magnetic region is analysed in terms of a small number of antiferromagnetically coupled local magnetic moments. High-pressure experiments on resistivity, AC susceptibility and magnetisation curves show a depression of magnetism and an enhancement of superconductivity in all samples studied so far.