Journal of Physics D Applied Physics · 2010 · 50 citations · 14 references
Natural SciencesMaterials EngineeringMaterials ScienceCeramic MaterialsMaterials CharacterizationMaterials PhysicsCrystal EngineeringCrystalline MaterialsElectrical Properties Of CeramicsHigh-temperature MaterialsPiezoelectric CeramicsPiezoelectric MaterialsCzochralski Crystal GrowthCzochralski GrowthDielectric CharacterizationDielectric StrengthPiezoelectric CrystalsPiezoelectric PropertiesPiezoelectricityTemperature Dependence Of Electrical Properties
Langasite-type crystals, including La3Ga5.5Nb0.5O14 (LGN), and La3Ga5.5Ta0.5O14(LGT) with disordered structure, and Ca3TaGa3Si2O14 (CTGS) and Ca3NbGa3Si2O14 (CNGS) with ordered structure, were grown using the Czochralski method. Resistivity was studied as a function of temperature. Temperature coefficients of frequency (TCFs) for different cuts were investigated in the above crystals at elevated temperatures, which were found to be ±11 ppm K−1 and ±6.0 ppm K−1 up to 400 °C for LGN (YXl)1.5° and LGT (YXl) − 20° cuts, respectively, in thickness shear mode, while the TCF was found to be 21 ppm K−1 up to 800 °C for CTGS (YXl) − 20° and CNGS (YXl) − 20°. Furthermore, the dielectric and electromechanical behaviour of the above crystals with low TCF cuts as a function of temperature were studied. It was observed that CTGS and CNGS crystals with an ordered structure possessed temperature independent dielectric and electromechanical behaviour up to 800 °C, making CTGS and CNGS potential candidates for high temperature sensor applications.
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