Role of Ni-Mn hybridization in magnetism of martensitic state of Ni-Mn-In shape memory alloys

Extended X-ray Absorption Fine Structure (EXAFS) studies on Ni$_{50}$Mn$_{25+x}$In$_{25-x}$ have been carried out at Ni and Mn K edge as a function of temperature. Thermal evolution of nearest neighbor Ni-Mn and Mn-Mn bond distances in the martensitic phase give a clear evidence of a close relation between structural and magnetic degrees of freedom in these alloys. In particular, the study highlights the role of Ni 3d - Mn 3d hybridization in the magnetism of martensitic phase of these alloys.Comment: Accepted for publication in EP

Critical exponents and the correlation length in the charge exchange manganite spin glass Eu_{0.5}Ba_{0.5}MnO_{3}

The critical regime of the charge exchange (CE) manganite spin glass Eu_{0.5}Ba_{0.5}MnO_{3} is investigated using linear and non linear magnetic susceptibility and the divergence of the third ordered susceptibility (chi{_3}) signifying the onset of a conventional freezing transition is experimentally demonstrated. The divergence in chi{_3}, dynamical scaling of the linear susceptibility and relevant scaling equations are used to determine the critical exponents associated with this freezing transition, the values of which match well with the 3D Ising universality class. Magnetic field dependence of the spin glass response function is used to estimate the spin correlation length which is seen to be larger than the charge/orbital correlation length reported in this system.Comment: 4 pages, 4 Figure

Anomalous Magnetic Properties in Ni50Mn35In15

We present here a comprehensive investigation of the magnetic ordering in Ni50Mn35In15 composition. A concomitant first order martensitic transition and the magnetic ordering occurring in this off-stoichiometric Heusler compound at room temperature signifies the multifunctional character of this magnetic shape memory alloy. Unusual features are observed in the dependence of the magnetization on temperature that can be ascribed to a frustrated magnetic order. It is compelling to ascribe these features to the cluster type description that may arise due to inhomogeneity in the distribution of magnetic atoms. However, evidences are presented from our ac susceptibility, electrical resistivity and dc magnetization studies that there exists a competing ferromagnetic and antiferromagnetic order within crystal structure of this system. We show that excess Mn atoms that substitute the In atoms have a crucial bearing on the magnetic order of this compound. These excess Mn atoms are antiferromagnetically aligned to the other Mn, which explains the peculiar dependence of magnetization on temperature.Comment: Accepted in J. Phys. D.:Appl. Physic

Kinematical Analogy for Marginal Dyon Decay

We describe a kinematical analogy for the marginal decay of 1/4-BPS dyons in 4-dimensional N=4 string compactifications. In this analogy, the electric and magnetic charges play the role of spatial momenta, the BPS mass plays the role of energy, and 1/2-BPS dyons correspond to massless particles. Using SO(12,1) "Lorentz" invariance and standard kinematical formulae in particle physics, we provide simple derivations of the curves of marginal stability. We also show how these curves map into the momentum ellipsoid, and propose some applications of this analogy.Comment: 10 pages, minor revision

Evaluation and Analysis of Different Type of Edge Detection Techniques on Cartridge Case Image

The forensic identification of ballistics specimens relies on the detection, recognition and ultimate matching of markings on the surfaces of cartridges and projectiles made by the firearms. The feature extraction from the images is always a very important step in automated examination system. The edge detection refers to the process of identifying and locating sharp discontinuities in an image which helps in pattern recognition. The edge detection of ballistics specimens like, the firing pin mark, head stamp mark and striation on cartridge case the positive identification is based mainly on the image segmentation and feature extraction of the proposed area. Thus, applying an edge detection algorithm to an image may significantly reduce the amount of data to be processed and may therefore filter out information that may be regarded as less relevant, while preserving the important structural properties of an image. If the edge detection step is successful, the subsequent task of interpreting the information contents in the original image may therefore be substantially simplifiedIn this paper we have compared different techniques of Gradient-based and Laplacian based edge detection on the cartridge case image with MATLAB tool

Heterotic potential of single crosses in groundnut (Arachis hypogaea L.)

Two sets of diallel crosses involving diverse parents were evaluated for heterosis and combing ability for 15 characters measured at seedling, flowering, and harvest phases. The utility of Spanish x Spanish, Valencia x Valencia, Virginia Bunch x Virginia Bunch and Virginia Runner x Virginia Runner crosses along with the infra-specific ones in breeding programs is emphasized. A high range of heterosis was shown by a few crosses. Parents of the diallels were classified as High (H) or Low (L) on the basis of their gca over the 15 characters spanning the entire growth phase of the plant. It was suggested that the heterotic potential of H x L crosses could be successfully exploited to create a broader genetic base