ISSN:
1434-6036
Keywords:
77
;
80
;
B
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Single crystals of MCd(NO2)3, with M=NH4, K, Rb, Cs, and Tl, respectively, were grown and investigated by means of optical and dielectric methods. The crystals show rhombohedral symmetry (possible space group R 3) and multi-domain patterns at ambient temperature. The compounds exhibit phase transitions above room-temperature of first (M=K) and second order (M=Rb, Cs, Tl), respectively, into cubic high-temperature phases. Observed dielectric anomalies and hysteresis loops point to ferroelectric properties and suggest a relaxational order-disorder mechanism of the nitrite ions to be responsible for the transitions. The MCd-(NO2)3-compounds are seen to represent a new family of ferroelectrics with a cubic prototypic phase closely related to the structural type of the perovskites. The transions are classified by symmetry considerations, and a possible structure of the cubic high-temperature phase with space group Pm3 is proposed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01320508
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