Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition in the film from a tetragonal to cubic symmetry. At low thickness, the in-plane tensile stress induces a tetragonal distortion of the lattice that generates a perpendicular anisotropy, large enough to overcome the shape anisotropy and to stabilize the magnetization easy axis out of plane. However, in thicker films, the lattice relaxation toward the cubic structure of the bulk allows the shape anisotropy to force the magnetization to be in plane aligned

Potency test of a rape accused in India – Rationale, problems and suggestions in light of the Criminal Law (Amendment) Act, 2013

AbstractIndian legal system makes it mandatory to medically examine any accused of rape as well as other forms of sexual assault. Accused is brought in the police custody for conducting medical examination which includes general physical examination, potency test and evidence collection. The medical examination report of the accused is labeled as the “POTENCY TEST REPORT”. As per the changed definition of rape after Criminal Law (Amendment) Act, 2013, potency test stands irrelevant in rape cases because the changed law does not require peno-vaginal intercourse to call it as rape. However, even after the change in definition of rape and laws related to it, potency test is still a mandatory part of medical examination of accused. Displeasure about the same has also been raised by a fast track court of Delhi. In this paper, we have discussed the rationale of potency test of sexual assault in light of Criminal Law Amendment Act (2013), court judgment and other available literature

λ-Shaped mesogenic homologous series with polar substituents: Synthesis, characterization and unusual dielectric behaviour

A new l-shaped mesogenic homologous series with polar bromo and nitro substituent was synthesized by fixing rigid 2-bromo-4-nitrophenylazo groups to a resorcinol moiety. 4-n-alkoxybenzoyl groups esterify both the phenolic -OH groups. In the present series, methoxy and ethoxy derivatives are nonmesogenic, n-propyloxy to n-octyloxy derivatives exhibit enantiotropic nematic mesophase. Smectic C (SmC) mesophase commences from the n- octyloxy derivative as an enantiotropic phase and is retained up to the last member synthesized. The effect of polar bromo and nitro substituent on mesomorphic properties is discussed. In this paper, we also report the unusual dielectric behaviour of n-octyloxy and n-tetradecyloxy derivatives of the present l-shaped mesogenic homologous series. The dielectric permittivity of the sample was found to be unusually low in SmC phase in comparison to nematic phase. We have explained it on the basis of twoconformer model, which can exist in SmC phase due to specific shape of the molecule. The model has been supported by calculating activation energy of both the possible conformers from Arrhenius plot of relaxation frequency versus temperature. There is a clear difference in the value of activation energy of both the conformers as expected. © Maxwell Scientific Organization, 2009

Dielectric and optical properties of polymer-liquid crystal composite

Dielectric properties of polymer-liquid crystal mixture, having constituent polymer, poly-butyl methacrylate (PBMA) and liquid crystal, cholesteryl nonanoate, are reported as a function of frequency and temperature. The measurement has been done in a temperature range of 300-375 K and frequency range of 100 Hz-10 MHz. The dielectric permittivity and dielectric loss shows significant changes with the addition of polymer molecules in liquid crystal. The significant feature of composite formation is that the pure liquid crystal and polymer do not show dielectric relaxation in the frequency range covered, while the composite shows relaxation peak at a particular frequency. The optical transmittance of pure liquid crystal and composite has also been measured and compared. © 2006 Elsevier Ltd. All rights reserved

Dielectric and electro-optical characterization of dyed ferroelectric liquid crystals

The ferroelectric liquid crystal displays normally suffers from less contrast ratio and vision angle. To produce high optical contrast and colours in FLC displays, Guest-host mode is widely used. Addition of small amount of dichroic dye in pure FLCs results in considerable change in its dielectric and electro-optical properties. In the present paper we have investigated the effect of two dichroic Anthraquinone dyes (D37 and D5) on the ferroelectric liquid crystal materials (Felix 17/100). Dye doped FLC mixtures have been prepared by the dispersion of each dye at five different concentrations about 1, 2, 3, 4 and 5%wt/wt in pure FLC. The planar aligned cells have been used to study dielectric and electro-optical properties in SmC* phase of all pure and the dye doped mixtures. Considerable change in various properties like Goldstone mode relaxation frequency and dielectric strength have been noticed for both the sets of dye doped mixtures. These effects have been discussed in the light of changes produced in the different material parameters like spontaneous polarization, rotational viscosity and tilt angle

Magnetic Tunnel Junctions With Co:TiO2 Magnetic Semiconductor Electrodes

Spin-polarized tunneling is investigated in magnetic tunnel junctions containing an ultrathin interfacial layer of Co:TiO2 magnetic semiconductor. The Co:TiO2 layers (0 to 1 nm thick) are inserted at the SrTiO3/Co interface in La0.67Sr0.33MnO3/SrTiO3/Co tunnel junctions. For all junctions we find a negative tunnel magnetoresistance, which decreases upon the insertion of Co:TiO2, while the junction resistance increases strongly. This suggests that the ultrathin Co:TiO2 is a paramagnetic insulator that acts as an additional tunnel barrier, in contrast to thick (180 nm) layers grown under comparable conditions, which exhibit metallic impurity band conduction and room-temperature ferromagnetism

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Not AvailableWeed management and planting methods in potato cultivation affect the tuberield and quality significantly, and hence, requires proper management. Therefore, to explore the possibilities of developing a pre-emergence (PE) herbicide application system for potato planter specially for cut seed pieces (tubers) a study was conducted at ICAR-Directorate of Weed Research (DWR) during Rabi season of 2017-18 and 2018-19. The study includes different sprout-eye orientation of the potato tubers along with different weed management practices. The application of metribuzin at 0.75 kg/ha as PE effectively controlled the weeds and obtained a weed density of 2.43 and 2.04 weeds/m2 and weed dry biomass of 1.35 and 1.64 g/m2 respectively at 25 and 55 DAP. By application of the metribuzin as PE and paraquat as early-post emergence (PoE), the tuber yield was increased from 9-16.5%. The sprout-eye orientation has significant effect on tuber yield. The tuber yield was reduced by 28.3% and 16.7% respectively, in 2700 sprout-eye orientation and random dropping over sprout-eye orientation of 90±300. The highest tuber yield of 28.4 t/ha was obtained in planting of whole tuber having the size of 40 to 50 g per tuber. The application of metribuzin as PE effectively controlled the weeds, thus a PE applicator system can be developed along with the potato planter.Not Availabl

Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition in the film from a tetragonal to cubic symmetry. At low thickness, the in-plane tensile stress induces a tetragonal distortion of the lattice that generates a perpendicular anisotropy, large enough to overcome the shape anisotropy and to stabilize the magnetization easy axis out of plane. However, in thicker films, the lattice relaxation toward the cubic structure of the bulk allows the shape anisotropy to force the magnetization to be in plane aligned