Temperature-dependent dielectric properties of Au/Si_3N_4/n-Si (metal insulator semiconductor) structures

The dielectric properties of Au/Si3N4/n-Si （MIS） structures are studied using the admittance measurements （C–V and G/ω–V） each as a function of temperature in a range from 80 K to 400 K for two frequencies （100 kHz and 1 MHz）. Experimental results show that both the dielectric constant （ε’） and the dielectric loss （ε＂） increase with temperature increasing and decrease with frequency increasing. The measurements also show that the ac conductivity （σac） increases with temperature and frequency increasing. The lnσac versus 1000/T plot shows two linear regions with different slopes which correspond to low （120 K–240 K） and high （280 K–400 K） temperature ranges for the two frequencies. It is found that activation energy increases with frequency and temperature increasing.

Influence of Annealing Time on the Microstructure and Properties of Pb(Zr_(0.53)Ti_(0.47))O_3 Thin Films

The PZT thin films were prepared on （111）- Pt/Ti/SiO2/Si substrates by sol-gel method, and lead acetate [Pb（CH3COO）2], zirconium nitrate [Zr（NO3）4] were used as raw materials. The X-ray diffractometer （XRD） and scanning electron microscopy （SEM） were used to characterize the phase structure and surface morphology of the films annealed at 650 ~C but with different holding time. Ferroelectric and dielectric properties of the films were measured by the ferroelectric tester and the precision impedance analyzer, respectively. The PZT thin films were constructed with epoxy resin as a composite structure, and the damping properties of the composite were tested by dynamic mechanical analyzer （DMA）. The results show that the films annealed for 90 minutes present a dense and compact crystal arrangement on the surface; moreover, the films also achieve their best electric quality. At the same time, the largest damping loss factor of the composite constructed with the 90 mins-annealed film shows peak value of 0.9, hi^her than the pure epoxy resin.

Microstructure and electrical properties of Sc_2O_3-doped CaCu_3Ti_4O_(12) ceramics

CaCu3Ti4O12 ceramics doped with different contents of Sc203 （mol%, x = 0, 0.05, 0.10, 0.15, and 0.20） were prepared by the traditional solid-state reaction method. Scanning electron microscope （SEM） and X-ray diffraction （XRD） were used in the microstructural studies of the specimen, and the electrical properties were inves- tigated. XRD results show that the Sc has no influence on the phase composition. The results from the dielectric measurements show that further increase of Sc doping could decrease the dielectric loss slightly. A high dielectric constant and low dielectric loss can be achieved when the doping concentration is 0.10 mol%.