Magnetic excitations in the charge ordered state of Yb4As3 and Yb4(As0.6P0.4)3

Detailed inelastic neutron scattering studies on the low-carrier heavy-electron system Yb4As3 and the semi-conducting mixed compound Yb-4(AS(0.6)P(0.4))(3) reveal that the charge ordering phenomenon, which leads to one-dimensional properties, is common to both compounds. No definite magnetic response other than the one-dimensional spin excitations was observed from the pure material Yb4As3, which exhibits a heavy-electron anomaly in its transport properties, for energy transfers above about 0.3 meV. (C) 1999 Elsevier Science B.V. All rights reserved.