Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Structural Phase Transition in K1-xCsxDy(WO4)2 Single Crystals
Ist Teil von
Crystal research and technology (1979), 2000-11, Vol.35 (11-12), p.1343-1346
Ort / Verlag
Berlin: WILEY-VCH Verlag Berlin GmbH
Erscheinungsjahr
2000
Link zum Volltext
Quelle
Wiley Online Library Journals Frontfile Complete
Beschreibungen/Notizen
Single crystals of dysprosium potassium (caesium) double tungstates were grown both by typical flux growth and Top Seeded Solution Growth. K2W2O7 was used as flux. Potassium tungstate provides broad range of growth temperatures, rather low volatility, and does not introduce additional components into the melt. K1‐xCsxDy(WO4)2 crystals belong to the monoclinic syngony ( α ‐KY(WO4)2 structure) and has the space group C2/c. Dy3+ ions are situated on the two‐fold axes (C2) (which coincide with the crystallographic [010] directions) inside distorted octahedra of oxygen ions. KDy(WO4)2 is known to undergo a structural phase transition of Jahn‐Teller type at 6.38K. The influence of caesium ions on structural phase transition was investigated. Spectroscopic studies of this compound at low temperature have revealed some peculiarities of optical absorption spectra. The ground state of the Dy3+ ions is split into Kramer's doublets with the first excited doublet lying closely to the ground doublet what determines the thermal behaviour of absorption spectra. The increase of the distance between the Dy3+ lowest doublets observed at low temperature is interpreted as the result of the cooperative Jahn‐Teller effect.