Neodymium substituted calcium iron titanate having the general formula Ca1-xNdx(Ti0.5Fe0.5)O3 were prepared by the standard solid state reaction technique at relatively higher temperature (1473 K). X-ray diffraction (XRD) and optical microscopy are used to carry out the structural analysis and surface morphology, respectively. The XRD analysis confirms that all compositions are single phase orthorhombic in structure. The lattice parameters and the average grain size are found to decrease but the density to increase with the increase in Nd content. The dielectric constant (?/), dielectric loss (tan?) and ac conductivity (?ac) are studied at room temperature as a function of frequency and compositions. The room temperature ?/ is found to decrease with the increase in frequency and Nd content. On the other hand, the tan? and ?ac are observed to increase with the increase in frequency and decrease with the increase in Nd content. Dhaka Univ. J. Sci. 61(1): 125-129, 2013 (January) DOI: http://dx.doi.org/10.3329/dujs.v61i1.15113

The spinel ferrite of Ni 0.20 Cu 0.30 Zn 0.50 Fe 2 O 4 was studied at room temperature using X-ray diffraction pattern prepared by auto combustion technique. The analysis of the XRD patterns showed that the sample has a single phase cubic spinel structure. The bulk density, average grain size and initial permeability increase with increasing sintering temperature up to a optimum temperature. Beyond that temperature all those properties decreases. The value of relative quality factor decreases with increasing sintering temperature. The DC magnetization measurement showed that at room temperature the sample is in ferrimagnetic state. The number of Bohr magneton, n( B ), Néel temperature, T N , and the field at which saturation occurs were also calculated and possible explanation for the observed characteristics of microstructure, initial permeability, DC magnetization, and Néel temperature of the studied sample are presented.

Polycrystalline xBa0.95Sr0.05TiO3-(1‒x)BiFe0.9Sm0.1O3[xBST-(1‒x)BFSO] ceramics were synthesized. The structural phase transitions were studied and it was found that structure of the compound transformed from rhombohedral to cubic phase. The compound exhibited a dielectric anomaly in the vicinity of Néel temperature of BiFeO3 except for x = 0.25. Enhanced dielectric properties were noticed and this might be attributed to the reduction of oxygen vacancies. Studies of electrical conductivity over a wide temperature range showed that the ceramics behaved like a semiconductor with the negative temperature coefficient of resistance. Contribution of grains in conduction mechanism of the materials dominated and the grain resistance was found to be decreased with the increase in temperature. A Non-Debye type relaxation was seen in the material. The impedance data were re-plotted using the modulus formulae to avoid the ambiguity arising out of the presence of grain/grain boundary effect. Activation energy was found to be 0.18 to 0.33 eV in modulus study which was very close to complex impedance observation and it was implied that the charge carrier had the same energy barrier during the relaxation. Bangladesh Journal of Physics, 27(1), 23-42, June 2020

With improved initial permeability and extremely low relative loss factor (RLF) of Nanocrystalline Ni-Cu ferrites were synthesized by combustion technique by doping excess amount of Mn at different sintering temperatures. Ferrites are ceramic magnetic oxides materials. It shows the property of electrical insulator and magnetic conductor with large number of applications in various fields. Structural characteristics were measures from the X-ray diffraction (XRD) patterns. It shows formation of pure single-phase cubic spinel structure with Nanocrystalline and good chemical homogeneity. From these data lattice constant was calculated. By the doping of Mn content it is found that lattice constant increases and these compositions obey the Vegard"s law. From this study it was found that at the increasing of Mn content highly dense with lower porous and bigger grain of ferrite increases its magnetic and electric properties. High magnetization, high permeability, high quality factor, high mechanical stability, low loss factor were found in magnetic measurement.