Electron Tunneling into Intermediate-Valence Materials

Abstract

Electron tunneling spectra of TmSe, SmS, Sm${\mathrm{B}}_6$, and Ce${\mathrm{Pd}}_3$ have been measured with the GaAs Schottky-barrier probe tunneling method. Antiferromagnetic TmSe shown an energy gap $2\Delta \left(\mathrm{full}\mathrm{width}\mathrm{at}\mathrm{half}\mathrm{maximum}\right)=1.2\mathrm{}$ meV, in situ pressure-transformed metallic SmS exhibits a gap of 1.7 meV, and Sm${\mathrm{B}}_6$ shows a gap of 2.7 meV, which is independent of magnetic field. For Ce${\mathrm{Pd}}_3$ an inelastic excitation is found near ± 14 meV, which is absent in Y${\mathrm{Pd}}_3$.