Anomalous thermal expansion of single-crystalline UGe 2

Abstract

The linear thermal expansion coefficients α of single-crystalline UGe 2 have been measured in the temperature range 6 K < T<300 K. It is found that α exhibits a large anisotropy in the temperature dependence and a discontinous change near 50 K (= T c ), which corresponds to ferromagnetic order. The volume of UGe 2 increases with decreasing temperature below T c . The magnitude of spontaneous volume magnetostriction is about 1.2 × 10 −3 at 0 K.