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Updated: Sep 26, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Cation movement and phase transitions in KTP isostructures; X-ray study of sodium-doped KTP at 10.5 K
Stefan T Norberg1, Alexander N Sobolev, Victor A Streltsov
1Materials and Surface Chemistry, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. stn@inoc.chalmers.se
Abstract:
An accurate structure model of sodium-doped potassium titanyl phosphate, (Na(0.114)K(0.886))K(TiO)(2)(PO(4))(2), has been determined at 10.5 K by single-crystal X-ray diffraction. In addition to the low-temperature data, X-ray intensities have been collected at room temperature. When the temperature was decreased from room temperature to 10.5 K, both potassium cations moved 0.033 (2) A along the c-axis, i.e. in the polar direction within the rigid Ti-O-P network. This alkaline metal ion displacement can be related to the Abrahams-Jamieson-Kurtz T(C) criteria for oxygen framework ferroelectrics. Potassium titanyl phosphate (KTP) is a well known material for second harmonic generation (SHG), and the influence of sodium dopant on the TiO(6) octahedral geometry and SHG is discussed. The material studied crystallizes in the space group Pna2(1) with Z = 4, a = 12.7919 (5), b = 6.3798 (4), c = 10.5880 (7) A, V = 864.08 (9) A(3), T = 10.5 (3) K and R = 0.023.
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