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Study on the ferroelectric phase transition in potassium lithium niobate (KLN)
Author(s) -
Podlojenov S.,
Stade J.,
Burianek M.,
Mühlberg M.
Publication year - 2006
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/crat.200510585
Subject(s) - ferroelectricity , phase transition , dielectric , phase (matter) , chemistry , analytical chemistry (journal) , second harmonic generation , birefringence , lithium niobate , potassium niobate , transition temperature , materials science , optics , condensed matter physics , physics , optoelectronics , organic chemistry , laser , superconductivity
The ferroelectric phase of potassium lithium niobate K 3 Li 2–x Nb 5+x O 15+2x (KLN) in the range of 0.15 < x < 0.5 is a very promising material for the second harmonic generation (SHG) in the blue visible region (∼410 nm). The ferroelectric phase transition was shown to occur between 400 and 500°C depending on the composition of the KLN phase. In this study several analysis techniques were used to investigate the phase transition on ferroelectric (x = 0.3) KLN samples. The temperature‐dependent measurements of the relative dielectric constant ε 33 provided a phase transition temperature of about 470°C. In our DTA experiments, a small but reproducible thermal effect at the phase transition in KLN was indicated. The temperature‐dependent birefringence measurement technique, applied the first time on KLN, shows a second order behaviour at a temperature of 467 °C. However, this phase transition is accompanied by a small thermal effect. The DSC analysis for the other KLN composition (x = 0.5) provided a phase transition temperature of 514 °C. The appearance of a phase transition in the paraelectric KLN phase (Nb content higher than 55 mol%) was also studied. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)