Synthesis and characterization of sol-gel derived Mn2+ doped In2S3 nanocrystallites embedded in a silica matrix

Mn²⁺ doped In₂S₃–SiO₂ nanocomposite thin films were synthesized by sol-gel technique. The films were annealed in air at different temperatures (473–623 K) and characterized by optical, microstructural and electron spin resonance (ESR) study. Optical transmittance study revealed the manifestation of quantum size effect while ESR indicated the presence of manganese in indium sulphide as dispersed dopant rather than manganese cluster.     

Thermoelectric power of vacuum evaporated PbTe films

Variation of thermoelectric power with thickness of the vacuum evaporated PbTe films has been investigated. The films were deposited on mica, glass, quartz and LiF substrates, under identical conditions. Attempts have been made to derive a relation which represents the variation of thermoelectric power with thickness of the film. The temperature variation of thermoelectric power has also bsen studied.     

Classical and quantum theories of radiation damping in ferromagnetic and antiferromagnetic resonance

Both classical and quantum theories of radiation damping in ferromagnetic and antiferromagnetic resonance relaxation are given. Effects of demagnetization and anisotropy, that is, of elliptical classical precession, are included. In the classical theory a phenomenological approach to ferromagnetic resonance relaxation by means of the Landau-Lifshitz equation is also presented. In the quantum theory, the magnon-photon interaction Hamiltonian is derived, and the radiation-damped linewidth is obtained by computing the transition matrix element and also the one-magnon self energy. As noted long ago by Einstein, each photon is emitted in a random but specific direction, and only on average does the quantum radiation pattern reproduce the classical. To first order, however, this reproduction is shown to be exact, correcting a recent calculation by Shrivastava.     

An Inventory Model with Two-Component Demand Rate and Shortages

The article investigates a deterministic inventory system with two-component demand rate. The demand rate is stock-dependent down to a certain level and then constant. Shortages are allowed and are fully backlogged. The storage space is assumed to be limited. A flowchart is provided to solve a general system. To study the effects of changes in the system parameters on the average net profit a sensitivity analysis has been performed.     

On the nature of the phase transition in the KDP systems

Using the Landau theory of phase transitions it has been shown that for a second order phase transition Ω/k_BT_c ? 0.01. and its isomorphs 4Ω/J¹ ? 1 and for a first order transition Ω/k_BT_c ? 0.01.     

Anomaly in electron channeling due to imperfections produced thermally in a potassium chloride crystal

Lattice imperfections were produced in KCl crystals by a thermal process. The heat treated specimen was irradiated with 50 KeV electrons and the corresponding range of electrons in the crystal has been estimated. It was found that the electron range in the crystal depends upon the temperature of heat treatment, being a decreasing function of this temperature up to about 625 K, above which it becomes an increasing function. This anomaly has been explained in terms of dissolution of vacancies through dislocation loops.     

Application of fission track registration technique in the estimation of fissile materials

Analysis of fissile materials in solution by fission track registration technique has been extended to plutonium in solution of its alloys. In these estimations, the results agreed within 1–4% with the average of those obtained by other chemical and instrumental methods like potentiometry, mass-spectrometry and X-ray fluorescence. Some special practical problems encountered in the analysis of plutonium solutions are noted. Various factors affecting the results have been investigated and the necessary precautions for reducing these errors have been indicated. The advantages of the method over some other conventional methods have also been discussed. It is suggested that a source of about 10 μg of²⁵²Cf corresponding to a neutron flux of about 10⁷ n·cm⁻²·sec⁻¹ is ideal for these experiments.