Lanthanum hexaborate cathode emission material

Poyerekeza ndi tungsten cathodes,lanthanum hexaborate (LaB6) ma cathode ali ndi maubwino monga kuthawa kwa ma elekitironi otsika, kachulukidwe ka ma elekitironi kwambiri, kukana bombardment ya ayoni, kukana bwino kwa poizoni, kugwira ntchito mokhazikika, komanso moyo wautali wautumiki. Yakhala ikugwiritsidwa ntchito bwino pazida ndi zida zosiyanasiyana zolondola kwambiri monga magwero a plasma, kusanthula ma electron microscopy, makina a electron beam lithography, Auger spectroscopy, ndi ma electron probes. The zofunika katundu waLaB6, LaB6, ndi ya CsCI mtundu wa cubic primitive lattice. Ma atomu a Lanthanum amakhala m'makona asanu ndi atatu a cube. Ma atomu asanu ndi limodzi a boron amapanga octahedron ndipo ali pakatikati pa cube. The covalent chomangira aumbike pakati BB, ndi ma elekitironi osakwanira pa kugwirizana pakati BB amaperekedwa ndi lanthanum atomu. La ali ndi nambala ya electron ya valence ya 3, ndipo ma electron awiri okha ndi omwe amafunikira kuti athe kutenga nawo mbali pa mgwirizano. 1 electron yotsalayo imakhala electron yaulere. Chifukwa chake, chomangira cha La-B ndi chomangira chachitsulo chokhala ndi madulidwe apamwamba kwambiri komanso madulidwe abwino. Chifukwa cha mgwirizano wapakati pakati pa ma atomu a B, mphamvu ya ma bond ndi yayikulu, mphamvu ya chomangira imakhala yolimba, ndipo kutalika kwa chomangira kumakhala kochepa, zomwe zimapangitsa kuti LaB6 ikhale yolumikizana. Ili ndi zina monga kuuma kwakukulu, malo osungunuka kwambiri, ndi kukana pafupizitsulo zapadziko lapansi zosawerengeka.