Thermal expansion of single crystal Tb-50% Ho in the vicinity of the Curie temperature

Measurement of c-axis strain made during the cooling of single crystal Tb-50% Ho indicate a Curie temperature of 73.7 ± 0.1 K, approximately 8 K lower than previous observations. On raising the temperature T_c increases, depending on previous thermal history. The abrupt change in c-axis parameter at T_c is ～ 54% smaller than the corresponding change in dysprosium.