Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MM: Fachverband Metall- und Materialphysik

MM 37: Microstructure and Phase Transformations

MM 37.2: Vortrag

Mittwoch, 14. März 2018, 12:00–12:15, TC 010

Effect of Ca substitution on structural, dielectric and optical properties of Ba5NdTi3Nb7O30 ceramic — Vipin Kumar¹, Satender Nath Pandey², and •Sardool Singh Ghumman¹ — ¹Physics department, Sant Longowal Institute of Engineering & Technology, Deemed University, Longowal, District Sangrur Punjab 148 106 India — ²Physics Department, Motilal Nehru National Institute of Technology, Allahabad 211 004 India

The polycrystalline samples of pure Ba5NdTi3Nb7O30 and Ca substituted Ba4CaNdTi3Nb7O30, in the tetragonal tungsten bronze (TTB) family, are prepared by solid state reaction method. Formation of single phase of the complex compound of orthorhombic type has been verified by X-ray diffraction analysis in both the cases. Surface morphology and uniform growth of grains are examined by scanning electron microscopy. The dielectric properties as a function of frequency and temperature demonstrate dielectric anomaly of ferroelectric to paraelectric phase transition with raised Curie temperature at 107 oC in comparison to 100 oC of calcium free compound. Optical absorption spectrum with FTIR indicates red shift in M-O absorption bond which signifies the distortion in the lattice. The enhanced dielectric stability over a considerable range of temperature calls for the calcium doped material for use in devices on low frequency and high temperature operation.