Polycrystalline ceramic samples of Ca-doped fresnoite of general formula Ba2−xCaxTiSi2O8 (x = 0.0, 0.2, 0.4, 0.8, and 1) have been prepared by standard solid state reaction technique using high purity oxides and carbonates. The formation of the single phase compound and its structural parameters were investigated by X-ray diffraction followed by Rietveld refinement using non-centrosymmetric space group P4bm. The bond distances between atoms in a unit cell for all the compounds were also calculated which supports the structural results analyzed by Rietveld analysis. The frequency and temperature dependent dielectric constant and ac conductivity of all the compounds have been measured. The real and imaginary parts of the dielectric constant increases with the increase of temperature. The activation energy (Ea) calculated from ac conductivity increases from x = 0.0 to 0.4 and then decreases from x = 0.8 to 1.0. The modulated differential scanning calorimetry has been used to investigate the effect of substitution on the specific heat, heat flow, and other thermal parameters of the compounds.
This is a preview of subscription content, log in to check access.
Financial support from the University Grants Commission Project No: 36/178/2008 (SR) and UGC fellowship to S. K. Barbar is gratefully acknowledged. The authors are also thankful to Dr. D.M. Phase, Dr. A.M. Awasthi and S. Bhardwaj, UGC-DAE-CSR Indore for providing the SEM and MDSC measurement facilities.
Alfors JT, Stinson MC, Matthews RA, Pabst A. Seven new barium minerals from eastern Fresno County, California. Am Miner. 1965;50:314–40.Google Scholar
Moore PB, Louisnathan SJ. The crystal structure of fresnoite, Ba2(TiO)Si2O7. Zeitschrift fur Kristallographie Bd. 1969;130:438–48.CrossRefGoogle Scholar
Abrahams SC. Structurally based prediction of ferroelectricity in inorganic materials with point group 6 mm. Acta Crystallogr B. 1988;44:585–95.CrossRefGoogle Scholar
Halliyal A, Bhalla AS, Markgraf SA, Cross LE, Newnham RE. Unusual pyroelectric and piezoelectric properties of fresnoite (Ba2TiSi2O8) single crystal and polar glass-ceramics. Ferroelectrics. 1985;62:27–38.CrossRefGoogle Scholar
Kimura M, Fujino Y, Kawamura T. New piezoelectric crystal: synthetic fresnoite (Ba2TiSi2O8). Appl Phys Lett. 1976;29:227–8.CrossRefGoogle Scholar
Kimura M. Elastic and piezoelectric properties of Ba2TiSi2O8. J Appl Phys. 1977;48:2850–6.CrossRefGoogle Scholar
Haussühl S, Eckstein J, Recker K, Wallrafen F. Growth and physical properties of fresnoite Ba2TiSi2O8. J Cryst Growth. 1977;40:200–4.CrossRefGoogle Scholar
Bechthold PS, Haüssuhl S, Michael E, Eckstein J, Recker K, Wallrafen F. Second harmonic generation in fresnoite, Ba2TiSi2O8. Phys Lett A. 1978;65:453–4.CrossRefGoogle Scholar
Markgraf SA, Halliyal A, Bhalla AS, Newnham RE, Prewitt CT. X-ray structure refinement and pyroelectric investigation of fresnoite, Ba2TiSi2O8. Ferroelectrics. 1985;62:17–26.CrossRefGoogle Scholar
Takahashi Y, Kitamura K, Benino Y, Fujiwara T, Komatsu T. Second-order optical nonlinear and luminescent properties of Ba2TiSi2O8 nanocrystallized glass. Appl Phys Lett. 2005;86:091110.CrossRefGoogle Scholar
Yamauchi H. Surface-acoustic-wave characteristics on fresnoite (Ba2TiSi2O8) single crystal. J Appl Phys. 1978;49:6162–4.CrossRefGoogle Scholar
Melngailis J, Vetelino JF, Jhunjhunwala A, Reed TB, Fahey RE, Stern E. Surface acoustic wave properties of fresnoite, Ba2Si2TiO8. Appl Phys Lett. 1978;32:203–5.CrossRefGoogle Scholar
Foster MC, Arbogast DJ, Nielson RM, Photinos P, Abrahams SC. Fresnoite: a new ferroelectric mineral. J Appl Phys. 1999;85:2299–303.CrossRefGoogle Scholar
Chang ZP, Bhalla AS. Elastic anomaly in fresnoite (Ba2TiSi2O8) single crystal. Mater Lett. 1989;8:418–20.CrossRefGoogle Scholar
Ochi Y, Meguro T, Kakegawa K. Orientated crystallization of fresnoite glass-ceramics by using a thermal gradient. J Eur Ceram Soc. 2006;26:627–30.CrossRefGoogle Scholar
Rangarajan B, Bharadwaja SSN, Furman E, Shrout T, Lanagan M. Impedance spectroscopy studies of fresnoite in BaO–TiO2–SiO2 system. J Am Ceram Soc. 2010;93:522–30.CrossRefGoogle Scholar
Roy M, Barbar SK, Dave P, Jangid S. Indu Bala, X-ray, scanning electron microscopy and electrical properties of synthetic fresnoite (Ba2TiSi2O8) ceramics. Appl Phys A. 2010;100:1191–6.CrossRefGoogle Scholar
Barbar SK, Roy M. Synthesis, structural and electrical properties of Ca-modified Ba2TiSi2O8 ceramics. J Am Ceram Soc. 2011;94:843–8.CrossRefGoogle Scholar