In this study, CeO2 nanostructures were synthesized by a soft chemical method. A hydrothermal treatment was observed to lead to an interesting morphological transformation of the nanoparticles into homogeneous microsp...In this study, CeO2 nanostructures were synthesized by a soft chemical method. A hydrothermal treatment was observed to lead to an interesting morphological transformation of the nanoparticles into homogeneous microspheres composed of nanosheets with an average thickness of 40 nm. Structural analysis revealed the formation of a single-phase cubic fluorite structure of CeO2 for both samples. A Raman spectroscopic study confirmed the XRD results and furthermore indicated the presence of a large number of oxygen vacancies in the nanosheets. These oxygen vacancies led to room-temperature ferromagnetism （RTFM） of the CeO2 nanosheets with enhanced magnetic characteristics. Amazingly, the nanosheets exhibited substantially greater antibacterial activity than the nanoparticles. This greater antibacte- rial activity was attributed to greater exposure of high-surface-energy polar surfaces and to the presence of oxygen vacancies.展开更多
Zn0.95-zAlxMn0.050 （x=0, 0.03, 0.05, and 0.07） dilute magnetic semiconductor materials have been synthesized by sol-gel auto-combustion technique. The effect of A1 doping on the structural, electrical, and magnetic ...Zn0.95-zAlxMn0.050 （x=0, 0.03, 0.05, and 0.07） dilute magnetic semiconductor materials have been synthesized by sol-gel auto-combustion technique. The effect of A1 doping on the structural, electrical, and magnetic properties has been investigated. X-ray diffraction studies demonstrate the existence of single phase characteristic hexagonal wurtzite type crystal structure, similar to the host ZnO, in all the synthesized compositions. Although, the microscopic images revealed that the grains were clustered, yet some individual grains could be seen to have hexagonal texture. Electrical resistivity was observed to decrease with the rise of temperature up to 450 ℃, depicting the characteristic semiconductor behavior. Room temperature ferromagnetic behavior was observed in all the compositions. The value of saturation magnetization increased with the increase of A1 concentration in ZnMnO system referred to the gradual enhancement of free carriers.展开更多
基金funded by the Higher Education Commission of Pakistan (HEC) IPFP (Grant No. PM-IPFP/HRD/ HEC/2011/3386) to Dr. Javed Iqbal Saggu and funding for HEC Ph.D. Scholar (Tariq Jan) under his supervision
文摘In this study, CeO2 nanostructures were synthesized by a soft chemical method. A hydrothermal treatment was observed to lead to an interesting morphological transformation of the nanoparticles into homogeneous microspheres composed of nanosheets with an average thickness of 40 nm. Structural analysis revealed the formation of a single-phase cubic fluorite structure of CeO2 for both samples. A Raman spectroscopic study confirmed the XRD results and furthermore indicated the presence of a large number of oxygen vacancies in the nanosheets. These oxygen vacancies led to room-temperature ferromagnetism （RTFM） of the CeO2 nanosheets with enhanced magnetic characteristics. Amazingly, the nanosheets exhibited substantially greater antibacterial activity than the nanoparticles. This greater antibacte- rial activity was attributed to greater exposure of high-surface-energy polar surfaces and to the presence of oxygen vacancies.
文摘Zn0.95-zAlxMn0.050 （x=0, 0.03, 0.05, and 0.07） dilute magnetic semiconductor materials have been synthesized by sol-gel auto-combustion technique. The effect of A1 doping on the structural, electrical, and magnetic properties has been investigated. X-ray diffraction studies demonstrate the existence of single phase characteristic hexagonal wurtzite type crystal structure, similar to the host ZnO, in all the synthesized compositions. Although, the microscopic images revealed that the grains were clustered, yet some individual grains could be seen to have hexagonal texture. Electrical resistivity was observed to decrease with the rise of temperature up to 450 ℃, depicting the characteristic semiconductor behavior. Room temperature ferromagnetic behavior was observed in all the compositions. The value of saturation magnetization increased with the increase of A1 concentration in ZnMnO system referred to the gradual enhancement of free carriers.
