K. Ichikawa et al., RARE-EARTH N4,5 EMISSION-SPECTRA OF SOME RARE-EARTH HEXABORIDES, Journal of the Physical Society of Japan, 62(11), 1993, pp. 4123-4128
The rare-earth N4,5 emission spectra of PrB6 and NdB6 were measured to
investigate the 4f states. These spectra show some emission peaks abo
ve and below the one-electron 4d threshold. The emission spectra are c
ompared with existing results of absorption and resonant photoemission
. Comparison shows that the emission spectra are composed of two types
of 4f --> 4d emission processes, 4d(9)4f(n) --> 4d(10)4f(n-1) + hv an
d 4d(9)4f(n+1) --> 4d(10)4f(n) + hv', where n is the number of 4f elec
trons in the ground state. The intensity of the 4f --> 4d emission is
estimated for light rare-earth hexaborides. This result suggests that
the intensity of the 4f --> 4d emission is weaker than the 5p --> 4d e
mission.