Observation Of Temperature Effects Research Articles

Observation of temperature effect on electrical properties of novel Au/Bi0.7Dy0.3FeO3/ZnO/p-Si thin film MIS capacitor for MEMS applications

In this work the dependence of electrical properties on operation temperature (27°C to 200°C) of Au-Cr/Bi0.7Dy0.3FeO3 (BDFO)/ZnO/p-Si (MIS device) are discussed. The thin film of BDFO was deposited by pulsed laser deposition (PLD) on p-Si. From the electrical characterization, the devices properties like ideality factor (η), barrier height) (BH) of Au-Cr/BDFO/ZnO/p-Si MIS were determined. The values of η and BH were found to be 1.34 and 0.86eV at 200°C and 2.16 and 0.30eV; respectively, at room temperature (27°C). The leakage current conduction mechanism of the device was investigated and found to be Schottky emission (SE) in the low electric field (<0.92MVcm−1) regime and trap assisted Poole–Frenkel (PF) mechanism for high electric field regime. The coexistence of ferroelectric and ferromagnetic coupling and excellent dielectric properties in multiferroic BDFO offers potential in the field of memory devices; sensing and energy harvesting (cantilevers).

INTERACTIONS OF CARBON DIOXIDE CONCENTRATION, LIGHT INTENSITY AND TEMPERATURE ON PLANT RESISTANCES TO WATER VAPOUR AND CARBON DIOXIDE DIFFUSION

SummaryExchange of water vapour and carbon dioxide, between whole sunflower plants and an atmosphere controlled to required CO2 and water vapour concentrations, was measured in a polythene chamber. Plant resistances to diffusion of CO2 and H2O were calculated. From the combined data of net flux of CO2(“P”), resistances to CO2 uptake, and atmospheric CO2 concentration [CO2]atm, the intercellular space CO2 concentration [CO2]int could be calculated.[CO2]int was linearly related to [CO2]atm and this relationship was modified by light intensity. Plant age, between 3 and 6 weeks, did not alter the relationship. The ratio of [CO2]int to [CO2]atm was shown to be equivalent to the ratio of mesophyll resistance to CO2 diffusion (rm) to total resistance to CO2 diffusion (RCO2).At a given [CO2]atm, [CO2]int decreased with increasing light intensity between 500 and 5500 ft‐candles but was little affected by leaf temperatures between 18 and 34° C. On the other hand, the minimum internal CO2 concentration Γ, measured as the equilibrium CO2 compensation point, increased linearly over the same temperature range but was little affected by light intensity above 500 ft‐candles. The effects of temperature and light on [CO2]int are in contrast to their effects on the Γ value. Therefore, it is less likely that temperature effects on [CO2]in, measured in the normal photosynthetic [CO2]atm range, are responsible for‘midday stomatal closure’as inferred from observations of temperature effects on Γ alone.By comparing the effects of temperature and light intensities on stomatal resistance over the same range of [CO2]int values, direct effects of light and temperature, not mediated through changes in [CO2]int were demonstrated. The interactions of the factors involved are discussed.

Ultraviolet absorption study of the molecular association of benzoic acid and its derivatives

The effect of concentration on the solution spectra of benzoic acid and its derivatives was studied. The absorption bands associated with dimeric molecules appear at the wavelengths longer than those of monomeric molecules, and this is also confirmed from the observation of temperature effect on the absorption spectra. Contrary to this red shift in the absorption, association of benzoic acid with ethyl ether causes a blue shift in the absorption spectrum of benzoic acid. A qualitative explanation was given to these experimental results.