The 〈110〉 oriented FCl \u3c sup\u3e - \u3c/sup\u3e molecule-ion in KF

The heteronuclear diatomic molecule-ion FCl with its molecular axis oriented along a crystal face diagonal, i.e.. FCl 〈110〉, has been produced by ionizing radiation in single crystal KF doped with PbCl2 and KCl. Evidence to support this species identification as well as its orientation relative to the lattice is obtained from anisotropic optical absorption spectral measurements as well as from electron spin resonance (ESR) absorption spectra. Optical absorption spectral data, estimates of the molecular reorientation temperature, as well as ESR absorption spectral parameters are given for the FCl 〈110〉. A qualitative explanation of the differences of the optical and ESR parameters of FCl 〈111〉 and FCl 〈110〉 is discussed. © 1983 American Institute of Physics