Structure-Properties Relations in Two Iodate Families Studied by Topology-Symmetry Analysis of OD Theory

Olga Reutova,Anatoly Volkov,Olga Dimitrova,Elena Belokoneva

doi:10.3390/sym13081477

Abstract

Single crystals of new non-centrosymmetric iodate Ba(IO3)OH are synthesized hydrothermally and structurally investigated. OD topology-symmetry analysis of layers and their alternation led to conclusions about the similarity with the Bi(IO3)O nonlinear-optical crystal. Both structures are members of a general family with differences in structures and properties. AgBi(IO3)4 and AgBi(SO4)(IO3)2 belong to another family with the two types of layers giving different local symmetry. The properties are estimated semi-quantitatively based on structural data. Such an approach is new and promising. Hypothetical structural variants are predicted.

Highlights

Non-centrosymmetric compounds, especially polar, are objects in material science due to their possible properties, such as nonlinear optical, ferroelectric, piezoelectric, pyroelectric and magnetic
Second harmonic generation (SHG) is found for many inorganic crystals as borate, phosphate, sulfate and selenite and they are used as materials
Iodates belong to the inorganic compounds which possess the umbrella-like trigonal [IO3 ]− anionic group with the apical lone pair of I5+, which provides a strong polarity

Summary

Introduction

Non-centrosymmetric compounds, especially polar, are objects in material science due to their possible properties, such as nonlinear optical, ferroelectric, piezoelectric, pyroelectric and magnetic. The topology-symmetry analysis of OD theory was carried out in accordance with the above-mentioned principles, as well as on the basis of our own experience in the study of structural families. P4/nmm, significantly higher thanthan the the structure space group symmetry elements are given in Figure ab projection.

Results

Conclusion