resumo
High-quality potassium tantalate (KTaO3, KT) single crystals are grown by a high-temperature self-flux solution modified method in which potassium carbonate (K2CO3) and boron oxide (B2O3) are utilized as a complex flux. Additions of small amounts of boron oxide, used because of its low melting temperature (450 degrees C) and tendency to decrease the weight losses, increased the metastable region, requiring lower temperature (<= 1300 degrees C) for the growth of relatively large KT crystals thereby suppressing the K volatilization tendency. By changing the flux composition and flux to solute proportion growth conditions are modified. The as-grown potassium tantalate crystals exhibit a dielectric permittivity of 6600 and dielectric losses of 0.004 at 13 K and 100 kHz. These results suggest a new promising approach for growing relatively large size and high quality single crystals within KT-based system.
palavras-chave
POTASSIUM TANTALATE; RESONANCE; SRTIO3
categoria
Chemistry; Crystallography; Materials Science
autores
Zlotnik, S; Vilarinho, PM; Costa, MEV; Moreira, JA; Almeida, A
nossos autores
Isabel Margarida Miranda Salvado
Professor associado
Maria Elisabete Jorge Vieira Costa
Colaborador
Paula Maria Lousada Silveirinha Vilarinho
Vice-Diretor
Sebastian Zlotnik
Bolseiro de pós-DoutoramentoGrupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
The authors are thankful to Prof. Ian Reaney for TEM characterizations. This work was funded by FCT under the project PTDC/CTM/64805/2006 and FEDER.