The relation of physical properties to the symmetry of potassium iodate

Abstract

The symmetry properties of potassium iodate have been investigated in order to determine whether it might be a useful nonlinear optical material. In order to resolve the confusion over the point symmetry of this material, several experimental techniques have been used. These are single‐crystal X‐ray diffraction (room temperature), optical examination using conoscopic methods, second harmonic generation powder test, and pyroelectric measurements (the latter three techniques covering various temperature ranges). Correlating these observations with previously reported properties of KIO3 yields the result that below 212 °C, KIO3 is monoclinic Cm with a0 = 8.86 (5), b0 = 12.54 (6), c0 = 7.70 (5) Å and β = 125°05′±20′. The material is negative biaxial with 2V = 20°30′±30′ and pyroelectric with dPs/dT = 5.8 × 10−9 Coul. cm−2°C−1 (at room temperature). Above 212 °C this material is rhombohedral R3m with a0≃7.70 and α≃ 109°28′. The nature of the twinning below 212 °C and a method of detwinning are discussed. Type one phase matching angles were calculated.

The nitrate positions in phase III of thallous nitrate

“…3(a). This view would support the structure suggested by Crane (1972). CsIO3 could however resemble TINO3 III.…”

Influence of coion and counterion size on multi-ionic solution nanofiltration

“…For neutral solute: [31] 0.126 0.217 [28] 0.138 [32] Li + 1.029 [31] 0.239 0.131 [28] 0.059 [32] Cl -2.032 [31] 0.121 0.194 [28] 0.181 [32] IO 3 -1.078 [31] 0.228 0.264 [a] 0.247 [33] ethanol 1.240 [32] 0.198 --glucose 0.673 [32] 0.365 -- [a] calculated as reference [28]. ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ó ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae …”

Temperature Dependences of Dielectric, Elastic and Piezoelectric Properties of KIO3Single Crystals Associated with the Successive Phase Transitions

“…13(a) and 13(b). The ε exhibited slightly experiment but there has been no evidence of the phase transition around T X except the small anomaly in the value 2V (the angle between optical axes) at 130 • C. 4) Though the mechanism of the ionic conduction has not been clear, the structural changes at the II-III phase transition affects the ionic motion in the crystal on as shown in Figs. 2(a) and 2(b).…”

“…The phase transition at 130 • C reported by several authors is still questionable. 4) Investigations on the physical properties such as dielectric, 2,5) elelctro-optical, 6,7) piezoelectric properties, 6, 7) NQR 2) and Raman scatterng experiments 8,9) of KIO 3 have been reported. Although much data have been reported especially on the temperature dependences of dielectric constants, still there has been some discrepancies between them.…”