Pyroelectric properties of high-resistivity rubidium titanyl phosphate crystals in the 4.2-300Â K temperature range

Pyroelectric properties of high resistivity RbTiOPO4 single crystals cut from different growth sectors ({1 0 0}, {1 1 0} and {2 0 1}) have been studied using the modified static method in a broad temperature interval, from 4.2 to 300 K. A substantial scatter of the room temperature pyroelectric coefficient values has been observed, ranging from 1.3 to 4.6 10−5 C/m2 K, for samples of distinct stoichiometry. Different types of low-temperature anomalies in the pyroelectric coefficient behavior have been revealed in samples related to the various growth sectors. Crystals cut from the {1 1 0} sector exhibit particularly interesting anomalies at 90 and 250 K which are attributed to oxygen deficient PO4(1) and PO4(2) coordinational tetrahedral and their relaxor contribution. This and other anomalies are discussed in terms of the growth related variation of the RTP crystals' nonstoichiometry and point defect structure.