the perovskite-structured la2cuo4 nanoparticles (lco nps) have been synthesized via an ultrasonic-assisted co-precipitation route using octanoic acidas organic surfactant, and the phase composition, morphology, lattice parameters and size of nanoparticles  are characterized through fourier transform infrared spectroscopy (ft-ir), x-ray diffraction (xrd), scanning electron microscopy (sem) and t...

Transition metal oxides are a class of materials that are vitally important for developing new materials with functionality and smartness. The unique properties of these materials are related to the presence of elements with mixed valences of transition elements. Electron energyloss spectroscopy (EELS) in the transmission electron microscope is a powerful technique for measuring the valences of...

When metal/oxide/silicon (MOS) devices are subjected to ionizing radiation, hot carrier damage, or any process in which charge carriers are present in the oxide, interface states are created at the Si/SiO, interfaceelm The presence of holes in the oxide is most effective in triggering the interface state generation process.879 Studies of the transient response of irradiated devices shows that m...

background:  nowadays mri examinations have been widely used in clinical applications for many diagnoses. the use of contrast agent in mri improves lesion detection and characterization and causes more accurate diagnosis.  objectives: the aim of this study was comparing to optimal dose of magnevist contrast agent in modified t1w se (spin echo), t1w fse (fast spin echo) and t1w gre (gradient ech...

The electroluminescence (EL) and photoluminescence of Si nanocrystals (Si-nc) from multilayered samples of Si/SiO are investigated. Si-nc are formed within Si and SiO layers after furnace annealing. It is found that the presence of Si interlayers creates extra carrier paths for EL emission. A comparative study is further performed on a multilayered Si/SiO sample and a single-layered one with Si...

The properties of transition-metal oxides are related to the presence of elements with mixed valences, such as Mn and Co. Spatial mapping of the valence-state distribution of transition-metal elements is a challenge to existing microscopy techniques. In this letter, using the valence-state information provided by the white lines observed in electron energy-loss spectroscopy in a transmission el...

Oxide materials with resistance hysteresis are very promising for next generation memory devices. However, the microscopic dynamic process of the resistance change is still elusive. Here, we use in situ transmission electron microscopy method to study the role of oxygen vacancies for the resistance switching effect in cerium oxides. The structure change during oxygen vacancy migration in CeO(2)...