V. R. K. Murthy

Bio: V. R. K. Murthy is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Dielectric & Rietveld refinement. The author has an hindex of 27, co-authored 162 publications receiving 2595 citations. Previous affiliations of V. R. K. Murthy include VIT University & Indian Institute of Science.

Low cost instrumentation in lieu of spectropolarimeter

Abstract: Low-cost instrumentation based on the principle of a dispersion relation for the study of ORD (optical rotary dispersion) has been developed. The success of this method is tested for the case of a few biomolecules, and the use of refractometry as a two-in-one instrument is established. >

Molecular polarizabilities determination of substituted benzenes from a new dispersion relation

Abstract: The mean molecular polarizabilities of some substituted benzenes (chloro-, bromo-, methyl- and dimethyl substituted benzenes) are determined from a new dispersion relation. Comparison of results with literature data shows satisfactory agreement.

Low field Hall coefficient measurements of graphite ferric chloride intercalation compounds

Abstract: Extensive investigatiofis have been carried out on various graphite intercalation compounds (GICs), but the nature of the microscopic mechanisms have not been fully understood. The transport properties of these compounds show drastic changes from the parent graphite [1] and require more theoretical investigations. As an extension of our studies on graphite ferric chloride intercalation compounds (GFeC13) of both pure and mixed stages, we report our measurements of the Hall coefficient at low magnetic fields. The graphite ferric chloride intercalation compounds of pure and mixed stages were prepared by the conventional two-zone vapour transport technique with the graphite zone at higher temperature than the intercalant zone. The temperature conditions used for the synthesis are given in Table I. This particular system was found to be environmentally stable. The samples were characterized initially by the increase in weight percentage over that of initial graphite. X-ray characterization was carried out using CoK« radiation of wavelength 0.17902 nm. The stages were identified from the (0 0 1) reflections of the X-ray diffractogram. According to the classical model of staging [2], the c axis repeat distance Ic is related to the stage number n by the simple relation:

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Photonic crystals

Abstract: The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

Ferromagnetic materials

Abstract: In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Magnetic and electric properties of transition-metal-doped ZnO films

Abstract: 3d-transition-metal-doped ZnO films (n-type Zn1−xMxO (x=005–025): M=Co, Mn, Cr, Ni) are formed on sapphire substrates using a pulsed-laser deposition technique, and their magnetic and electric properties are examined The Co-doped ZnO films showed the maximum solubility limit Some of the Co-doped ZnO films exhibit ferromagnetic behaviors with the Curie temperature higher than room temperature The magnetic properties of Co-doped ZnO films depend on the concentration of Co ions and carriers

Wide band gap ferromagnetic semiconductors and oxides

Abstract: Recent advances in the theory and experimental realization of ferromagnetic semiconductors give hope that a new generation of microelectronic devices based on the spin degree of freedom of the electron can be developed. This review focuses primarily on promising candidate materials (such as GaN, GaP and ZnO) in which there is already a technology base and a fairly good understanding of the basic electrical and optical properties. The introduction of Mn into these and other materials under the right conditions is found to produce ferromagnetism near or above room temperature. There are a number of other potential dopant ions that could be employed (such as Fe, Ni, Co, Cr) as suggested by theory [see, for example, Sato and Katayama-Yoshida, Jpn. J. Appl. Phys., Part 2 39, L555 (2000)]. Growth of these ferromagnetic materials by thin film techniques, such as molecular beam epitaxy or pulsed laser deposition, provides excellent control of the dopant concentration and the ability to grow single-phase layers. T...