NEUTRON SPECTROSCOPIC STUDIES OF CRYSTALLINE ELECTRIC-FIELD IN INFINITE-LAYER SR1-XNDXCUO2

Due to their rather simple crystal structure, the infinite-layer (IL) compounds have attracted much interest as a favorable system for the s tudy of mechanisms of the electron or hole doping of the CuO2 planes i n the high-T-c superconductors. Crystalline electric field (CEF) inves tigation of high-T-c superconductors provides direct evidence of the c harge transfer process, since the rare-earth ion serves as a local pro be for the effective charge associated with the superconducting CuO2 p lanes. Inelastic neutron scattering has been employed to search for CE F transitions in the Sr0.87Nd0.13CuO2 compound produced by a high-pres sure technique. The observed energy spectra at T = 10 K exhibit two we ll-defined inelastic lines at 14.9, 19.5 meV and very weak scattering of magnetic origin around 41 and 80 meV associated with the Nd3+ ions in the IL phase. Based on the present results as well as on a well-est ablished extrapolation scheme possible CEF energy spectra for the IL p hase are discussed.