P. Victor

Normal ferroelectric to relaxor behavior in laser ablated Ca-doped barium titanate thin films

Ba1–xCaxTiO3 thin films (x = 0.05 to 0.17) were deposited on Pt-coated Si substrates using a pulsed excimer laser ablation technique. X-ray diffraction and scanning electron microscope studies of the Ba1–xCaxTiO3 targets exhibit a polycrystalline nature and thin films also show the same but with a significant orientation along the (111) direction. Secondary ion mass spectrometer analysis reveals the presence of a sharper interface existing at the thin film substrate. The dielectric phase transition temperature of (Ba1–xCax)TiO3 targets were sharp and the transition temperature was found to decrease from 140 °C to 110 °C with an increase in the values of x (x>0.05 at. %). The laser ablated Ca-doped BaTiO3 thin films deposited at 100 mTorr exhibited a higher dielectric constant, lower dielectric loss, and an anomalous decrease in phase transition was observed. The anomalous phase transition decrease was ascribed to the occupancy of the Ca2+ in the Ti4+ site. There was a cross over from the sharp to diffused phase transition for a higher composition of Ca (>9 at. %) in BaTiO3 thin films. The diffuse transition behavior might be due to the larger number of the Ca2+ ions occupying the Ti4+ site, eventually introducing larger compositional and structural disorder and this occupancy leads to the generation of oxygen vacancies. The activation energy obtained from impedance spectroscopy was 1.05 eV, and was attributed to the oxygen vacancy motion.

Leakage current behavior in pulsed laser deposited Ba(Zr0.05Ti0.95)O3 thin films

Barium zirconium titanate [Ba(Zr0.05Ti0.95)O3, BZT] thin films were prepared by pulsed laser ablation technique and dc leakage current conduction behavior was extensively studied. The dc leakage behavior study is essential, as it leads to degradation of the data storage devices. The current-voltage (I-V) of the thin films showed an Ohmic behavior for the electric field strength lower than 7.5 MV/m. Nonlinearity in the current density-voltage (J-V) behavior has been observed at an electric field above 7.5 MV/m. Different conduction mechanisms have been thought to be responsible for the overall I-V characteristics of BZT thin films. The J-V behavior of BZT thin films was found to follow Lampert’s theory of space charge limited conduction similar to what is observed in an insulator with charge trapping moiety. The Ohmic and trap filled limited regions have been explicitly observed in the J-V curves, where the saturation prevailed after a voltage of 6.5 V referring the onset of a trap-free square region. Two different activation energy values of 1.155 and 0.325 eV corresponding to two different regions have been observed in the Arrhenius plot, which was attributed to two different types of trap levels present in the film, namely, deep and shallow traps.

Dielectric relaxation in laser ablated polycrystalline ZrTiO4 thin films

Relaxation and conduction mechanisms under small ac fields of laser ablated ZrTiO4 thin films were analyzed in the light of impedance and modulus spectroscopy. The overall dielectric properties were mainly dominated by a Maxwell–Wagner type of relaxation with grains and the grain boundary two distinct parts of the circuit. Each of these parts was found to follow the universal power law of frequency dispersion. The modulus plot confirmed that the capacitive parts were relatively independent of the frequency and temperature, whereas the impedance and ac conduction studies exhibited significant temperature and frequency dependence. The conduction inside the grains was suggestive of a hopping mechanism through various defect sites whereas the interface barrier potential dictated grain boundary conduction.

Growth and electrical characterization of laser ablated highly oriented zirconium titanate thin films in a metal–oxide semiconductor configuration

Highly oriented zirconium titanate

Deep level transient spectroscopy studies on BaTiO3 and Ba1?xCaxTiO3 thin films deposited on Si substrates

(ZrTiO_4)

Effect of AC&DC field on the dielectric response of (Pb,La)TiO3 thin films

thin films were deposited along the (020) direction on a p-type Si substrate using the pulsed excimer laser ablation technique. X-ray diffraction and energy dispersive analysis of

Study of Thickness Dependence on Electrical Properties of (Pb,La)TiO 3 Thin Films for Memory Applications

ZrTiO_4

EFFECT OF MANGANESE DOPING ON THE ELECTRICAL CHARACTERISTICS OF SOL-GEL DERIVED LEAD ZIRCONATE TITANATE THIN FILMS

thin films reveal that they exhibit excellent phase and stoichiometry, respectively. Secondary ion mass spectrometer analysis has revealed that the presence of less thick native oxide is unavoidable and that a nearly sharper interface exists at the semiconductor–insulator interface. Electrical characterization was carried out on the highly oriented

Impact of microstructure on the electrical properties of zirconium titanate thin films in MOS configuration

ZrTiO_4

Study of Relaxor Behavior of 0.7Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 Thin Films

thin films. The density of interface states and fixed oxide charges were calculated using capacitance–voltage (C–V) analysis and the obtained dielectric constant was greater than 19. The annealed films exhibited higher dielectric constant and lower fixed oxide charges than the as-grown thin films. The influence of temperature on the response of the C–V characteristics has been studied and the recombination–generation of charge carriers was found to be responsible for the transition of the C–V curve from high frequency to low frequency. The conduction mechanism was examined using dc leakage current characteristics, revealing the bulk limited Poole–Frenkel conduction mechanism as the dominant mechanism in the