Figure 4
From: Nanoscale potassium niobate crystal structure and phase transition
XRD patterns showing phase transition of nanoscale KNO 3 powders. Obtained upon heat-treating gels at different temperatures: (a) orthorhombic to tetragonal (600°C), (b) tetragonal to cubic (600°C), (c) orthorhombic to tetragonal (700°C), (d) tetragonal to cubic (700°C), (e) orthorhombic to tetragonal (800°C), and (f) tetragonal to cubic (800°C).