Premium
Structural Phase Transition in K 1‐x Cs x D y (WO 4 ) 2 Single Crystals
Author(s) -
Borowiec M.T.,
Majchrowski A.,
Szymczak H.,
Zaleski M.,
Zmija J.
Publication year - 2000
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/1521-4079(200011)35:11/12<1343::aid-crat1343>3.0.co;2-x
Subject(s) - tungstate , chemistry , ion , octahedron , phase transition , caesium , crystallography , monoclinic crystal system , ground state , excited state , absorption spectroscopy , flux method , phase (matter) , atmospheric temperature range , single crystal , crystal structure , inorganic chemistry , atomic physics , condensed matter physics , thermodynamics , optics , physics , organic chemistry
Single crystals of dysprosium potassium (caesium) double tungstates were grown both by typical flux growth and Top Seeded Solution Growth. K 2 W 2 O 7 was used as flux. Potassium tungstate provides broad range of growth temperatures, rather low volatility, and does not introduce additional components into the melt. K 1‐x Cs x Dy(WO 4 ) 2 crystals belong to the monoclinic syngony ( α ‐KY(WO 4 ) 2 structure) and has the space group C2/c. Dy 3+ ions are situated on the two‐fold axes (C2) (which coincide with the crystallographic [010] directions) inside distorted octahedra of oxygen ions. KDy(WO 4 ) 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 Dy 3+ 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 Dy 3+ lowest doublets observed at low temperature is interpreted as the result of the cooperative Jahn‐Teller effect.