Abstract
Neutron inelastic scattering experiments have been performed on a polycrystalline sample of ErAG to obtain information on the crystal field level structure and on the exchange interaction. The measurements in the paramagnetic phase yield the crystal field parameters W=-0.040+or-0.002 meV and chi =0.42+or-0.02 which correspond to a Gamma 8(3) ground state with an overall splitting of 190K. The paramagnetic molecular field parameter is lambda P=(-1.4+or-0.2)*1023 Oe2 erg-1. From the measurements in the ordered states we obtain the molecular field parameters lambda c=(1.07+or-0.03)*1024 Oe2 erg-1 and lambda i(1.11+or-0.06)*1024 Oe2 erg-1 in the commensurate and incommensurate region, respectively. These parameters give an excellent description of the magnetic properties of ErAg. From the measured molecular field parameters three exchange integrals have been calculated.