Title: ELECTRONIC TRANSPORT PROPERTIES OF COMPOUNDS WITH TEMPERATURE UNSTABLE INTERMEDIATE VALENCE OF Ce
Authors: M.D.Koterlyn (Ivan Franko National University of Lviv, Dragomanova Str. 50, 79005 Lviv, Ukraine; Academy of Bydgoszcz, Sq. Weyssenhoffa 11, 85-072 Bydgoszcz, Poland), R.I.Yasnitskii, B.S.Morokhivskii (Ivan Franko National University of Lviv, Dragomanova Str. 50, 79005 Lviv, Ukraine)

Results of a thermoelectric power component (S_f) and electrical resistivity (ρ_f) measurements connected with the temperature unstable intermediate valence of Ce are presented for CeNi, CeNi₂ and CeNi₂Si₂ compounds in the temperature range 4-800 K. It is shown that dependences S_f(T) and ρ_f(T) are well described in a wide temperature range within the framework of a simple model of a narrow peak in the density of states g_f(E) of Lorentzian shape near the Fermi level. The width of the peak depends on temperature and defines the characteristic single-ion Kondo temperature T_K.

Key words: rare earth compounds, valence fluctuation, electrical resistivity, thermoelectric power
PACS: 72.20.Lp, 72.10.Fk, 75.30.Mb