The influence of Y dilution on the crystalline electric field part of the point-contact spectra of Van Vleck paramagnet PrNi5

We report on the study of the influence of Y dilution on the crystalline electric field (CEF) in the Van Vleck paramagnet PrNi5 using point-contact (PC) spectroscopy. PC spectra of Pr1-xYxNi5 compounds (x = 0,0.02,0.05, 0.1 and 0.2) in the ballistic regime have been measured. A shift of the main CEF peak (? -> ?52) situated at about 4.2 meV for x = 0 to 5.1 meV for x = 0.2 is observed. This shift is in agreement with that obtained from susceptibility measurements in this system. The asymmetry in the dV/dI dependences of all heterocontacts could be explained by the model taking into account the difference in effective masses of conduction electrons.