PRESSURE AND FIELD-DEPENDENT STUDIES OF SINGLE-CRYSTALLINE YBCU4IN

We present thermodynamical and transport properties of mixed-valent Yb Cu4In at various values of pressure and external fields. The data were obtained on either single crystals or high-quality polycrystals with a maximum temperature of T-v approximate to 69 K, the temperature wher e a temperature-induced valence transition occurs. Pressure reduces T- v with a rate of partial derivative T-v/partial derivative P = -2 K wh ereas external fields up to 9 T only slightly affect T-v.