THE INFLUENCE OF HYDROSTATIC-PRESSURE ON THE TEMPERATURE-DEPENDENCE OF THE RESISTIVITY IN ND2 3SR1/3MNO3-DELTA/

The temperature dependence of the resistivity of Nd2/3Sr1/3MnO3-delta was studied under hydrostatic pressure up to 15 kbar. Two magnetic pha se transition temperatures, T-1 and T-2 are identified, they both incr ease under pressure with nearly the same rate dT(1,2)/dP = 2.4 K/kbar. It is concluded that T-1 increases under pressure because the electro n overlap integral increases and with it the double-exchange transfer integral, while a substitution with large RE elements (''negative chem ical pressure'') should decrease the transfer but could still increase T-1 by increasing the Zener carrier density.