We study a model of a covalent band insulator with on-site Coulomb repulsion at half filling using dynamical mean-field theory. Upon increasing the interaction strength the system undergoes a discontinuous transition from a correlated band insulator to a Mott insulator with hysteretic behavior at low temperatures. Increasing the temperature in the band insulator close to the insulator-insulator...

in this paper, undopedzno and co-znonano structureswith different molar ratio of cobalt have been synthesized by the sonochemical method. structure have been characterized by fourier transform (ftir) and uv–vis spectroscopy,scanning electron microscopy (sem), energy dispersive analytical x-ray (edax), and x-ray diffraction (xrd) methods. moreover, the direct band gap has been calculated by tauc...

in the present study, co-zno and co-ni-zno nanoparticles were synthesized by sonochemical methods and the structural and optical properties were investigated through fourier transform infrared spectroscopy (ftir), uv-vis spectroscopy, field emission scanning electron microscopy (fe-sem), x-ray diffraction (xrd), and photoluminescence spectroscopy (pl) methods. morphology of nanoparticles obtain...

s-doped and bare mesoporous tio2 were prepared using titanium tetraisopropoxide and thiocarbamide as raw materials. prepared materials were characterized by means of fourier transform infrared spectroscopy ft-ir, thermogravimetry-differential scanning calorimetry (tg-dsc), x-ray diffraction (xrd), uv–vis absorption spectroscopy, brunauer–emmett–teller (bet) specific surface area and barrett–joy...

zno nanostructures have been synthesized by a simple reflux method, using different ionic liquids, such as 1-benzyl-3-methylimidazolium bromide ([bzmim][br]), 1,1'-(1,4 phenylenebis (methylene)) bis (3-methyl-1h-imidazol-3-ium) bromide ([mm-1,4-dbzim2][br]2) and 1-phenacyl-3-methylimidazolium bromide ([pmim][br]), with different amount of sodium hydroxide in water. also the effect of reaction t...

cumn2o4 nanoparticles, a semiconducting materials with tunable functionalities in solid oxide fuel cell, was successfully synthesized via a sol-gel method using its respective metal cations sources i.e. cu2+ and mn2+ in an appropriate complexing agent.the vibrational frequencies below 1000 cm-1 of the obtained materials confirmed the formation of metal-oxygen (m-o:cu-o, mn-o) bond in the sample...