Structural and phase evolution in mechanically alloyed calcium copper titanate dielectrics

Abstract

Nanocrystalline calcium-copper-titanate (CCTO) dielectric powders were prepared by mechanical alloying. Phase transformations and structural evolution of the mechanically activated powders were investigated through the Rietveld refinement of the X-ray diffraction results. The crystallite size, lattice strain, and weight fraction of individual phases were estimated based on crystal structure refinement. Furthermore, the microstructural properties and thermal behavior of the milled powders were investigated by Transmission Electron Microscopy (TEM) and Differential Thermal Analysis (DTA), respectively. It was found that CCTO nanocrystals can be successfully synthesized after the amorphization of the initial crystalline materials. Semi-spherical nano-size particles were developed after sufficient milling time. Formation of an amorphous phase during the milling cycle was confirmed by the presence of the glass transition and crystallization peaks in the thermal analysis profiles.

Electrical, Photocatalytic, and Humidity Sensing Applications of Mixed Metal Oxide Nanocomposites

“…4 The nanostructures such as CuO, ZnO, SnO 2 , SrO, NiO, CdO, and TiO 2 exhibit novel and advanced optical and electronic properties due to the quantum confinement effect. 5 Despite all outstanding properties of metal oxides, the carrier recombination rate and resistivity limit their utilization on the industrial level. 6 The suitable alternative is to modify the microstructure to obtain a uniform particle distribution, surface decoration with nanoparticles, and mixing with suitable elements.…”

“…Until now, Cu, Sr, Al, Zn, Ni, and Ni mixed with various elements such as Li, Na, Ti, and Al have been successfully used for various applications . The nanostructures such as CuO, ZnO, SnO 2 , SrO, NiO, CdO, and TiO 2 exhibit novel and advanced optical and electronic properties due to the quantum confinement effect . Despite all outstanding properties of metal oxides, the carrier recombination rate and resistivity limit their utilization on the industrial level .…”