Impact of energetic heavy particles on europium compound surfaces gives rise to radiative optical emission from reflected and sputtered particles and from the excited states of the solid compounds. In the present paper we discuss the optical spectrum and the sputtered secondary ion mass spectrum observed when solid europium oxide (Eu2O3) and europium chloride (EuCl3) are bombarded with 90 keV Ar+ ions from an ion accelerator. We observe the reduction reaction in solid europium chloride (EuCl3) by bombardment with a 20 A/cm2 beam of 90 keV Ar+ ions.