EFFECT OF HIGH-PRESSURE AND MAGNETIC-FIELD ON THE ELECTRICAL-RESISTIVITY OF YBAGCU4

The electrical resistivity of YbAgCu4 has been measured at pressures up to 100 kbar and at temperatures between 1 and 300 K. With increasing pressure, the resistivity maximum shifts to lower temperatures and the coherent regime disappears above about 60 kbar. At the highest pressures, a field of 8 T produces a large negative magnetoresistance, roughly equivalent to a negative pressure of 30 kbar. The behavior is consistent with a pressure-induced decrease in the Kondo temperature.