Abstract of Publication No. 410
C. Reinhard, P. Gerner, R. Valiente, O. S. Wenger and Hans U. Güdel
Upconversion phenomena in the Yb3+ doped transition metal compounds
Rb2MnCl4 and CsMnBr3
J. Lumin. 94-95, 331-335 (2001)
Abstract:
Crystals of Yb3+ doped Rb2MnCl4 and CsMnBr3 show orange-red
Mn2+ 4T1g 
6A1g upconverted luminescence under near-infrared
Yb3+
excitation. By short 10 ns pulse excitations the upconversion (UC) process
for both compounds has been determined to consist of a sequence of ground
and excited-state absorption steps. This mechanism can gain nonzero
probability by assuming an exchange mechanism between Yb3+ and
Mn2+. The
efficiency of the UC process is dependent on the structural nature of the
Yb3+-Mn2+ connection. It is three orders of magnitude more efficient in
Rb2MnCl4:
Yb3+ with a corner-sharing
Yb3+-Cl-Mn2+ arrangement than in the
face-sharing Yb3+-Br3-Mn2+ arrangement of
CsMnBr3:Yb3+.
Last
modified:
13.12.11 by
Gabriela Frei 