Structural study of Kx Na1 - X NbO3 (KNN) for compositions in the range x = 0.24-0.36
Acta Crystallographica Section B: Structural Science 65:1 (2009) 22-28
Abstract:
The structure of the A-site substituted perovskite K x Na1 - x NbO3, x = 0.24-0.36, where a phase boundary was previously reported, has been determined by high-resolution X-ray powder and neutron powder diffraction studies. The structure of the x = 0.3 compound was refined in the monoclinic space group Pm at 293 K and in P4mm at 523 K. The Glazer tilt system of the room-temperature monoclinic phase is a 0 b + c 0, which has implications for the nature of the next symmetry change with composition towards pure potassium niobate. A phase-coexistence region at the transition between monoclinic and tetragonal phases was also identified, consistent with a first-order phase boundary. There is also evidence for an intermediate oxygen-octahedra tilted tetragonal phase. © 2009 International Union of Crystallography Printed in Singapore - all rights reserved.VIBRATE! A program to compute irreducible representations for atomic vibrations in crystals
JOURNAL OF APPLIED CRYSTALLOGRAPHY 42 (2009) 1194-1196
Phases and structures of KxNa1−xNbO3 (KNN) at the high sodium end
Acta Crystallographica Section A: Foundations and advances International Union of Crystallography (IUCr) 64:a1 (2008) c428-c428
Optical birefringence study of the ferroelectric phase transition in lithium niobate tantalate mixed crystals:: LiNb1-xTaxO3
JOURNAL OF PHYSICS-CONDENSED MATTER 20:23 (2008) ARTN 235237
Studies of Domain and Twin Patterns in NaNbO3-Gd1/3NbO3 Solid Solution Crystals
FERROELECTRICS 374 (2008) 202-208