Author
V. R. K. Murthy
Other affiliations: VIT University, Indian Institute of Science, University of Kentucky ...read more
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.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the influence of Barium Strontium Sodium Niobate (Ba1-xSrx)2NaNb5O15 (BSNN) on structure, ferroelectric, dielectric, pyroelectric and resistivity properties at and around MPB has been investigated.
Abstract: Barium Strontium Sodium Niobate (Ba1-xSrx)2NaNb5O15 (BSNN) belongs to tungsten bronze ferroelectric morphotrophic phase boundary (MPB) system at x = 0.6, having large spontaneous polarisation, pyroelectric coefficient and low dielectic constant and is expected to be applicable for piezoceramic filter and pyroelectic devices. Present communication illustrates preparative conditions and the influence of Sm2O3 on structure, ferroelectric, dielectric, pyroelectric and resistivity properties at and around MPB. Substitution of Sm2O3 decreased the cell volume and Curie temperature and enhance the room temperature dielectric constant. The pyroelectric coefficient at room temperature has been observed to be in the order of 10-9 C/cm2 0C. The figure of merits FMRV, FMRN and FMRIhave been observed to be higher values of the order 10-14 CM/J, 10-12 CM/J, 10-11 CM/J, respectively on both pure and Sm: BSNN compositions. Resistivity studies indicated a PTCR response in the compositions.
(Botswana Journal of Technology: 2003 12(2): 1-7)
3 citations
TL;DR: The magnetite (Fe3O4) nanoparticles (0.5 wt%) of size less than 20 nm doped in p-n-alkyl benzoic acids where n varies from heptyl (7) to nonyl (9) are prepared and the presence of Fe
Abstract: The magnetite (Fe3O4) nanoparticles (0.5 wt%) of size less than 20 nm doped in p-n-alkyl benzoic acids where n varies from heptyl (7) to nonyl (9) are prepared and the presence of Fe
3 citations
TL;DR: In this paper, the microwave characteristics of (Ca 0.6,Sr 0.4)ZrO3 with substitution of Ti in the place of Zr were studied in terms of change of octahedral tilting with composition and temperature.
Abstract: The microwave characteristics of (Ca0.6 ,Sr 0.4)ZrO3 were studied with substitution of Ti in the place of Zr. The substitution of Ti for Zr affects the microwave dielectric properties of (Ca0.6,Sr0.4)ZiO3, in that both the dielectric constant (ϵ r ) and temperature coefficient of resonant frequency (τ f ) increase and Q factor decreases. The results are discussed in terms of change of octahedral tilting with composition and temperature.
3 citations
TL;DR: In this paper, a noncontact method of measuring the conductivity of pure and mixed stages of graphite-ferric chloride intercalation compounds has been outlined, which is insensitive to the degree of anisotropy and is well suited to the measurement of in-plane conductivities in quasi-two-dimensional systems.
Abstract: A non-contact method of measuring the conductivity of pure and mixed stages of graphite-ferric chloride intercalation compounds has been outlined. This r.f. technique is insensitive to the degree of anisotropy and is found to be well suited to the measurement of in-plane conductivities in quasi-two-dimensional systems. An approximate method of estimating the percentage composition of stages in mixed stages by measuring the conductivity is described.
3 citations
TL;DR: In this article, the elastic behavior of polycrystalline Mn-Zn ferrite system in Mn-rich region has been studied in the temperature range 300-650 K at saturation magnetic fields using the resonant piezoelectric oscillator technique.
3 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
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 …
33,785 citations
Proceedings Article•
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TL;DR: In this paper, the authors describe photonic crystals as the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures, and 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.
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.
2,722 citations
01 Sep 1955
TL;DR: In this paper, the authors restrict their attention to the ferrites and a few other closely related materials, which 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.
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.
2,659 citations
TL;DR: In this article, a 3d transition metal-doped ZnO films (n-type Zn1−xMxO) were formed on sapphire substrates using a pulsed-laser deposition technique, and their magnetic and electric properties were examined.
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
1,852 citations
TL;DR: In this paper, a review focusing on promising candidate materials (such as GaN, GaP and ZnO) is presented, where the introduction of Mn into these and other materials under the right conditions is found to produce ferromagnetism near or above room temperature.
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...
968 citations