Phase transitions and electron-phonon interaction in antiferromagnetic chromium and manganese, observed by point-contact spectroscopy

摘要

Two antiferromagmetic metals, Cr and Mn, were investigated by means of point-contact spectroscopy at low temperatures. Different types of singularities were observed at the derivatives of current-voltage characteristics (IVC) of point-contacts. Strong nonlinearities of IVC were detected for the contacts at bias voltages coinciding to the energies exceeding the Dehye values for Cr and Mn respectively. For both metals quantitatively good description of the IVC nonlinearities was achieved in the thermal limit of the point-contact spectroscopy. The nonlinearities are associated with phase transitions in the antiferromagnets. For the case of Cr it was possible to investigate the effects induced by electron-phonon interaction (EPI). The hitherto unknown EPI function for Cr and the integral parameters of EPI were obtained.