Charge transport in Li2B4O7 in single crystal and glassy states

Dielectric dispersion and ac conduction phenomena of Li2O−Sb2O3−PbO−GeO2:Cr2O3 glass system

“…Substitution of Li sites by Cr 3 þ ions in these glasses is important for several reasons. Cr 3 þ centers whether they are in either in high-field sites (energy of 4 T 2g 4 2 E g ) or in lowfield sites (energy of 4 T 2g o 2 E g ) occupy Li þ site and pave the way for the easy transport of Li þ ions in the glass network [15][16][17]. This should lead to some unusual surface segregation effects for dopants occupying the Li þ site [18]; such surface segregation, with an associated contribution to the ion conductivity in turn influences the electrical properties of these glasses.…”

Li2B4O7:Mn for dosimetry applications: traps and mechanisms

“…Hence, when Mn 2+ substitutes for Li + , the repelling Coulomb force is expected to shift the other closest Li + out from its regular position. Li would be probably moved to the closest interstitial position described in [38] in connection with mechanisms of ionic conductivity in Li 2 B 4 O 7 . The closest interstitial position for Li is situated at about 61 pm over the face of the oxygen polyhedron surrounding the regular Li site [38].…”

“…Li would be probably moved to the closest interstitial position described in [38] in connection with mechanisms of ionic conductivity in Li 2 B 4 O 7 . The closest interstitial position for Li is situated at about 61 pm over the face of the oxygen polyhedron surrounding the regular Li site [38]. The extra positive charges of both Mn 2+ and displaced Li + would split off the trapping level from the bottom of the conduction band.…”

“…The temperature of transition from polaronic to ionic conductivity varied from 420 K to approximately 450 K depending on CuO concentrations, and activation energy of ionic conductivity varied from 0.8 to 1.22 eV [44]. The investigations of charge transport in undoped Li 2 B 4 O 7 single crystals and glasses [38] demonstrated high activation energy of conductivity through Li + ion hopping (1.22 eV). A lower value (0.71 eV) was found for Li 2 B 4 O 7 glass [38].…”

“…The investigations of charge transport in undoped Li 2 B 4 O 7 single crystals and glasses [38] demonstrated high activation energy of conductivity through Li + ion hopping (1.22 eV). A lower value (0.71 eV) was found for Li 2 B 4 O 7 glass [38].…”