Spectroscopy and electronic structure of jethyphen;cooled GaAs

摘要

An optical spectrum, obtained by resonant twohyphen;photon ionization spectroscopy, is reported for jethyphen;cooled diatomic gallium arsenide. The ground state is identified asXthinsp;3Sgr;minus;, deriving from a sgr;2pgr;2molecular configuration, and is characterized by ohgr;lsquo;e=215 cmminus;1, ohgr;lsquo;exlsquo;e=3 cmminus;1, andrlsquo;0=2.53plusmn;0.02 Aring;. The upper state of the observed band system is3Pgr;rcorrelating to the Ga 4s24p,2P0+As 4s24p3,2D0excited separated atom limit. A strong predissociation sets in abovevrsquo;=0 for the OHgr;rsquo;=2,1 and 0minus;components of the3Pgr;rexcited state, and it is proposed that this is induced by spinndash;orbit interaction with the sgr;sgr;ast;pgr;2,5Sgr;minus;state which correlates to ground state atomic fragments. Constants for the upper3Pgr;0+state are ohgr;rsquo;e=152.13plusmn;0.70 cmminus;1, ohgr;exrsquo;e=2.89plusmn;0.08 cmminus;1, andre=2.662plusmn;0.027 Aring; for the69Ga75As isotopic modification. The ionization potential of GaAs has been bracketed as IP(GaAs)=7.17plusmn;0.75 eV, and a rehyphen;evaluation of the thirdhyphen;law measurement of the bond strength providesD0(GaAs)=2.06plusmn;0.05 eV. Comparisons to group IV and other group IIIhyphen;V diatomics, and to the bulk solid materials are also presented.