Cd1−xBix(Cd1+xIn1−x)VO6 (0 ≤ x ≤ 0.14): A New Polar Oxide with Second-Harmonic Generation
2010 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 22, no 16, 4814-4820 p.Article in journal (Refereed) Published
The structure of the new polar oxide, Cd2InVO6, was determined by powder X-ray diffraction. Cd2InVO6 crystallizes in space group P31 with the unit cell parameters: a = 12.21896(4), c = 9.25675(4) Å. The Cd2+ and In3+ ions are statistically disordered in nine independent positions (M1−M9) with a certain level of site preference. M1−M3 form highly asymmetric oxygen-coordination polyhedra, which are similar to those formed by alkali or alkali-earth cations. M4−M9 are in distorted octahedral cavities. It is shown that M1−M3 are likely occupied mostly by Cd2+ while M4−M9 are extensively mixed by Cd2+ and In3+. The structure is best described as a framework of interconnected M4−M9 distorted octahedra with the M1−M3 polyhedra off-framework and the three independent VO4 tetrahedra filling the channels of the framework structure by corner-sharing with the MO6 octahedra. The polar framework is composed of M4O6M9O6 octahedra in a five-connected net with the topology nomination (33, 63, 94). The Bi3+-substituted compounds were also investigated with the rationale that the lone pair electrons of Bi3+ might enhance ferroelectricity. Single phase Cd1−xBix(Cd1+xIn1−x)VO6 forms limited solid solutions (0.02 ≤ x ≤ 0.14). Ferroelectricity was observed for neither the parent nor the Bi3+-substituted compounds, which suggest that the dipole moments are not switchable or too insignificant in magnitude. The powder second-harmonic generation measurements with 1064 nm radiation established that Cd1−xBix(Cd1+xIn1−x)VO6 are type-1 phase-matchable materials for x = 0, 0.14 with 70 and 90 times the efficiency of α-SiO2, respectively.
Place, publisher, year, edition, pages
2010. Vol. 22, no 16, 4814-4820 p.
Research subject Structural Chemistry
IdentifiersURN: urn:nbn:se:su:diva-50731DOI: 10.1021/cm101582jISI: 000280855100038OAI: oai:DiVA.org:su-50731DiVA: diva2:382374