Synthesis of multi-wall carbon nanotubes by simple pyrolysis (2008)
Mahanandia, P, Vishwakarma, PN, Nanda, KK, Prasad, V, Barai, K, Mondal, AK, ...
A new pyrolysis technique has been developed for the synthesis of multi-walled carbon nanotubes (MWCNTs). In this simple method diethyl ether and nickelocene is pyrolysized in a reaction quartz tube...
Synthesis of multi-wall carbon nanotubes by simple pyrolysis (2008)
Mahanandia, P, Vishwakarma, PN, Nanda, KK, Prasad, V, Barai, K, Mondal, AK, ...
A new pyrolysis technique has been developed for the synthesis of multi-walled carbon nanotubes (MWCNTs). In this simple method diethyl ether and nickelocene is pyrolysized in a reaction quartz tube...
Quantum interference effect in strongly localized system of polymer-nanocomposites (2007)
Shekhar, S, Prasad, V, Subramanyam, SV
A positive magnetoresistance (MR) is observed in the composites of magnetic nanoparticles and polymer at low temperatures. The MR decreases gradually as temperature increases and becomes negative...
Structural, magnetic and Mossbauer studies of iron inclusions in a carbon matrix (2007)
Sajitha, EP, Prasad, V, Subramanyam, SV, Mishra, Ajay Kumar, Sarkar, Subhajit, Bansal, Chandrahaas
Ferromagnetic nanoparticles in a carbon matrix were synthesized by thermal decomposition of organic precursor maleic anhydride using different molecular weight percentages of organometallic precursor...
Metal–insulator transition in boron-doped amorphous carbon films (2007)
Vishwakarma, PN, Subramanyam, SV
Boron-doped amorphous graphite-like carbon (GLC) films have been prepared with different boron concentrations. Electrical transport measurements in the temperature range 1.3–300 K on the films...
Metal–insulator transition in boron-doped amorphous carbon films (2007)
Vishwakarma, PN, Subramanyam, SV
Boron-doped amorphous graphite-like carbon (GLC) films have been prepared with different boron concentrations. Electrical transport measurements in the temperature range 1.3–300 K on the films...
Structural, magnetic and Mossbauer studies of iron inclusions in a carbon matrix (2007)
Sajitha, EP, Prasad, V, Subramanyam, SV, Mishra, Ajay Kumar, Sarkar, Subhajit, Bansal, Chandrahaas
Ferromagnetic nanoparticles in a carbon matrix were synthesized by thermal decomposition of organic precursor maleic anhydride using different molecular weight percentages of organometallic precursor...
Quantum interference effect in strongly localized system of polymer-nanocomposites (2007)
Shekhar, S, Prasad, V, Subramanyam, SV
A positive magnetoresistance (MR) is observed in the composites of magnetic nanoparticles and polymer at low temperatures. The MR decreases gradually as temperature increases and becomes negative...
Hopping conduction in boron doped amorphous carbon films (2006)
Vishwakarma, PN, Subramanyam, SV
The electrical transport properties of boron doped graphitelike amorphous carbon films have been studied. Variable range hopping (VRH) conduction is found to be the conduction mechanism in these...
Shekhar, S, Prasad, V, Subramanyam, SV
Efros–Shklovskii variable range hopping (ES-VRH) conduction mechanism $[\rho = \rho_0 exp(T_{ES}/T )^{1/2}]$ is observed in composites of polymer and iron carbide nanoparticles embedded in carbon...
Multiwall carbon nanotubes from pyrolysis of tetrahydrofuran (2006)
Mahanandia, P, Vishwakarma, PN, Nanda, KK, Prasad, V, Subramanyam, SV, Dev, SK, ...
Multiwalled carbon nanotubes have been prepared by pyrolysing tetrahydrofuran (THF) in the presence of nickelocene. Pyrolysis of the precursor mixture has been achieved at temperature as low as...
Optical properties and electrical transport in intercalated amorphous carbon (2006)
Kumari, Latha, Subramanyam, SV
Iodine and sulfur incorporated amorphous carbon (a-C) films are prepared by vapor phase pyrolysis of carbon rich organic precursor, maleic anhydride. Transmission electron microscopy (TEM) analysis...
Electron–electron interaction in percolative network of polymer–amorphous carbon composites (2006)
Shekhar, S, Prasad, V, Subramanyam, SV
The polymer–amorphous carbon composites show a negative magnetoconductance which varies as $B^2$ at low fields which changes to $B^{\frac{1}{2}}$ at sufficiently high fields. The magnetoconductance...
Kumari, Latha, Subramanyam, SV
In this work, we discuss the preparation of iodine and sulfur incorporated amorphous carbon (a-C) films by vapor phase pyrolysis technique. Iodine incorporated a-C films depict an unusual resistivity...
Transport properties of conducting amorphous carbon-Poly(vinyl chloride) composite (2006)
Shekhar, S, Prasad, V, Subramanyam, SV
The dc electrical conductivity of composites of poly(vinyl chloride) filled with amorphous carbon (a-C) flakes has been studied from room temperature to 1.2 K. The dc conductivity shows percolative...
Kumari, Latha, Subramanyam, SV
In this work, we discuss the preparation of iodine and sulfur incorporated amorphous carbon (a-C) films by vapor phase pyrolysis technique. Iodine incorporated a-C films depict an unusual resistivity...
Shekhar, S, Prasad, V, Subramanyam, SV
The electrical transport properties of composites of polymer and iron carbide nanoparticle embedded in carbon have been studied from 300K to 1.3K. The composites show percolative type behavior with a...
Conduction mechanisms in carbon matrix containing ferromagnetic nanoparticles (2006)
Sajitha, EP, Prasad, V, Subramanyam, SV
We have investigated the low temperature resistance and magnetoresistance behaviour of the carbon matrix containing ferromagnetic nanoparticles. A range of compositions with different levels of...
Shekhar, S, Prasad, V, Subramanyam, SV
Efros - Shklovskii variable range hopping (ES-VRH) conduction mechanism $[\rho = \rho_0{exp}{(T_{ES}/T)^{1/2}}]$ is observed in composites of polymer and iron carbide nanoparticle embedded in carbon...
Transport properties of conducting amorphous carbon-Poly(vinyl chloride) composite (2006)
Shekhar, S, Prasad, V, Subramanyam, SV
The dc electrical conductivity of composites of poly(vinyl chloride) filled with amorphous carbon (a-C) flakes has been studied from room temperature to 1.2 K. The dc conductivity shows percolative...
Electron–electron interaction in percolative network of polymer–amorphous carbon composites (2006)
Shekhar, S, Prasad, V, Subramanyam, SV
The polymer–amorphous carbon composites show a negative magnetoconductance which varies as $B^2$ at low fields which changes to $B^{\frac{1}{2}}$ at sufficiently high fields. The magnetoconductance...
Size-dependent magnetic properties of Iron Carbide nanoparticles embedded in a carbon matrix (2006)
Sajitha, EP, Prasad, V, Subramanyam, SV, Mishra, Ajay Kumar, Sarkar, Subhajit, Bansal, Chandrahaas
Here we report on the magnetic properties of iron carbide nanoparticles embedded in a carbon matrix. The granular distribution of nanoparticles in an inert matrix, of potential use in various...
Hopping conduction in boron doped amorphous carbon films (2006)
Vishwakarma, PN, Subramanyam, SV
The electrical transport properties of boron doped graphitelike amorphous carbon films have been studied. Variable range hopping (VRH) conduction is found to be the conduction mechanism in these...
Shekhar, S, Prasad, V, Subramanyam, SV
Efros–Shklovskii variable range hopping (ES-VRH) conduction mechanism $[\rho = \rho_0 exp(T_{ES}/T )^{1/2}]$ is observed in composites of polymer and iron carbide nanoparticles embedded in carbon...
Multiwall carbon nanotubes from pyrolysis of tetrahydrofuran (2006)
Mahanandia, P, Vishwakarma, PN, Nanda, KK, Prasad, V, Subramanyam, SV, Dev, SK, ...
Multiwalled carbon nanotubes have been prepared by pyrolysing tetrahydrofuran (THF) in the presence of nickelocene. Pyrolysis of the precursor mixture has been achieved at temperature as low as...
Optical properties and electrical transport in intercalated amorphous carbon (2006)
Kumari, Latha, Subramanyam, SV
Iodine and sulfur incorporated amorphous carbon (a-C) films are prepared by vapor phase pyrolysis of carbon rich organic precursor, maleic anhydride. Transmission electron microscopy (TEM) analysis...
Shekhar, S, Prasad, V, Subramanyam, SV
The electrical transport properties of composites of polymer and iron carbide nanoparticle embedded in carbon have been studied from 300K to 1.3K. The composites show percolative type behavior with a...
Conduction mechanisms in carbon matrix containing ferromagnetic nanoparticles (2006)
Sajitha, EP, Prasad, V, Subramanyam, SV
We have investigated the low temperature resistance and magnetoresistance behaviour of the carbon matrix containing ferromagnetic nanoparticles. A range of compositions with different levels of...
Shekhar, S, Prasad, V, Subramanyam, SV
Efros - Shklovskii variable range hopping (ES-VRH) conduction mechanism $[\rho = \rho_0{exp}{(T_{ES}/T)^{1/2}}]$ is observed in composites of polymer and iron carbide nanoparticle embedded in carbon...
Size-dependent magnetic properties of Iron Carbide nanoparticles embedded in a carbon matrix (2006)
Sajitha, EP, Prasad, V, Subramanyam, SV, Mishra, Ajay Kumar, Sarkar, Subhajit, Bansal, Chandrahaas
Here we report on the magnetic properties of iron carbide nanoparticles embedded in a carbon matrix. The granular distribution of nanoparticles in an inert matrix, of potential use in various...
Structural morphology of amorphous conducting carbon film (2005)
Vishwakarma, PN, Prasad, V, Subramanyam, SV, Ganesan, V
Amorphous conducting carbon films deposited over quartz substrates were analysed using X-ray diffraction and AFM technique. X-ray diffraction data reveal disorder and roughness in the plane of...
Characterization and thermal stability of iodinated amorphous conducting carbon films (2005)
Kumari, Latha, Subramanyam, SV, Gayen, Arup, Jayaram, V
In this work, we discuss the structural and transport properties of iodine intercalated amorphous conducting carbon (a-C: I) films prepared by vapor phase pyrolysis of maleic anhydride and iodine....
Characterization and thermal stability of iodinated amorphous conducting carbon films (2005)
Kumari, Latha, Subramanyam, SV, Gayen, Arup, Jayaram, V
In this work, we discuss the structural and transport properties of iodine intercalated amorphous conducting carbon (a-C: I) films prepared by vapor phase pyrolysis of maleic anhydride and iodine....
Structural morphology of amorphous conducting carbon film (2005)
Vishwakarma, PN, Prasad, V, Subramanyam, SV, Ganesan, V
Amorphous conducting carbon films deposited over quartz substrates were analysed using X-ray diffraction and AFM technique. X-ray diffraction data reveal disorder and roughness in the plane of...
Magnetotransport in the amorphous carbon films prepared from succinic anhydride (2005)
In this paper, we report the low-temp. elec. cond. of amorphous carbon films prepd. from an org. precursor succinic anhydride at different pyrolysis temps. (700-980 DegC). The films prepd. at low...
M-I Transition in a-Conducting Carbon Films Induced by Boron Doping (2005)
Vishwakarma, PN, Subramanyam, SV
The amorphous conducting carbon films have been prepared at three different preparation temperatures with different boron-doping levels. The structural and transport properties of the same have been...
Magnetoresistance and Transport Properties of $La_{0.9}Ba_{0.1}MnO_{3}$ Nanoparticles (2005)
Nagabhushana, BM, Chakradhar, Sreekanth RP, Ramesh, KP, Prasad, V, Subramanyam, SV, Chandrappa, GT
This paper describes studies on the magnetoresistance and transport properties of nanocrystalline $La_{0.9}Ba_{0.1}MnO_{3}$ powders prepared by low temperature solution combustion process. Powder XRD...
The Effect of Fuel on the Formation of $LaMnO_{3}$ - Spectroscopic Studies (2005)
Nagabhushana, BM, Chakradhar, Sreekanth RP, Ramesh, KP, Prasad, V, Subramanyam, SV, Chandrappa, GT
Nanocrystalline $LaMnO_{3}$ has been synthesized by low temperature initiated-self propagating, gas producing solution combustion process. Combustion synthesis is rather cheap in terms of reactants...
Magnetotransport in the amorphous carbon films prepared from succinic anhydride (2005)
In this paper, we report the low-temp. elec. cond. of amorphous carbon films prepd. from an org. precursor succinic anhydride at different pyrolysis temps. (700-980 DegC). The films prepd. at low...
M-I Transition in a-Conducting Carbon Films Induced by Boron Doping (2005)
Vishwakarma, PN, Subramanyam, SV
The amorphous conducting carbon films have been prepared at three different preparation temperatures with different boron-doping levels. The structural and transport properties of the same have been...
Structural and electrical properties of amorphous carbon–sulfur composite films (2004)
Kumari, Latha, Subramanyam, SV
In this paper, we discuss the synthesis of carbon–sulfur composite (a-C:S) films by vapour phase pyrolysis of maleic anhydride and sulfur. Structural changes in the system are analysed by scanning...
Metal-Insulator transition in iodinated amorphous conducting carbon films (2004)
Kumari, Latha, Subramanyam, SV, Eto, S, Takai, K, Enoki, T
In this work, the effect of iodine incorporation on the electrical conductivity, magnetic susceptibility (\chi) and magnetoresistance (MR) of amorphous conducting carbon (a-C) films has been...
Sajitha, EP, Prasad, V, Subramanyam, SV, Eto, S, Takai, Kazuyuki, Enoki, T
Iron nanoparticles in a carbon matrix were synthesized by in situpyrolysis of maleic anhydride and ferrocene, using different molecular weight percentages. The characterization and magnetic...
Structural and electrical properties of amorphous carbon–sulfur composite films (2004)
Kumari, Latha, Subramanyam, SV
In this paper, we discuss the synthesis of carbon–sulfur composite (a-C:S) films by vapour phase pyrolysis of maleic anhydride and sulfur. Structural changes in the system are analysed by scanning...
Study of structural and transport properties of iodinated amorphous conducting carbon films (2004)
Iodine intercalated amorphous conducting C (a-C:I) films are prepd. by vapor phase pyrolysis of maleic anhydride and I2. TEM, selected area electron diffraction (SAED) and XPS studies reveal the...
Metal-Insulator transition in iodinated amorphous conducting carbon films (2004)
Kumari, Latha, Subramanyam, SV, Eto, S, Takai, K, Enoki, T
In this work, the effect of iodine incorporation on the electrical conductivity, magnetic susceptibility (\chi) and magnetoresistance (MR) of amorphous conducting carbon (a-C) films has been...
Sajitha, EP, Prasad, V, Subramanyam, SV, Eto, S, Takai, Kazuyuki, Enoki, T
Iron nanoparticles in a carbon matrix were synthesized by in situpyrolysis of maleic anhydride and ferrocene, using different molecular weight percentages. The characterization and magnetic...
Study of structural and transport properties of iodinated amorphous conducting carbon films (2004)
Iodine intercalated amorphous conducting C (a-C:I) films are prepd. by vapor phase pyrolysis of maleic anhydride and I2. TEM, selected area electron diffraction (SAED) and XPS studies reveal the...
Thermal Expansion of Irradiated Polyethylene from 10 to 340 K (2003)
The coefficient of thermal expansion of $\gamma$-irradiated polyethylene has been measured from 10 to 340 K by using the three-terminal capacitance technique. The samples are irradiated to 500 Mrad...
Thermal Expansion of Irradiated Polyethylene from 10 to 340 K (2003)
The coefficient of thermal expansion of $\gamma$-irradiated polyethylene has been measured from 10 to 340 K by using the three-terminal capacitance technique. The samples are irradiated to 500 Mrad...
Kumari, Latha, Prasad, V, Subramanyam, SV
In this work, the influence of iodine incorporation on the electrical properties of amorphous conducting carbon films, prepared by the vapor phase pyrolysis of maleic anhydride, is reported and...
Kumari, Latha, Prasad, V, Subramanyam, SV
In this work, the influence of iodine incorporation on the electrical properties of amorphous conducting carbon films, prepared by the vapor phase pyrolysis of maleic anhydride, is reported and...
Structure and electrical properties of sodium tungsten bronzes thin films (2002)
Lekshmi, Chaitanya I, Gayen, Arup, Prasad, V, Subramanyam, SV, Hegde, MS
Highly oriented thin films of $Na_xWO_3 (x=0.25–0.7)$ are grown on sapphire (1 1 0 2) and $SrTiO_3$ (1 0 0) substrates by pulsed laser deposition. The colour of the films changes from blue through...
Structural properties of carbon films prepared by the pyrolysis of tetra chloro phthalic anhydride are investigated in an attempt to correlate it with the metal-insulator transition observed earlier...
Structural properties of carbon films prepared by the pyrolysis of tetra chloro phthalic anhydride are investigated in an attempt to correlate it with the metal-insulator transition observed earlier...
Structure and electrical properties of sodium tungsten bronzes thin films (2002)
Lekshmi, Chaitanya I, Gayen, Arup, Prasad, V, Subramanyam, SV, Hegde, MS
Highly oriented thin films of $Na_xWO_3 (x=0.25–0.7)$ are grown on sapphire (1 1 0 2) and $SrTiO_3$ (1 0 0) substrates by pulsed laser deposition. The colour of the films changes from blue through...
Mithra, Madan LM, Cao, Y, Cho, Shinuk, Sutar, Dayanand, Lee, K, Menon, Reghu, ...
We discuss the disorder induced metal-insulator transition in polypyrrole doped with $CF_3SO_3^-$ in an attempt to understand the electrical transport in the vicinity of the transition. With the...
Conductivity and magnetoresistance in polypyrrole-$PF_6$ at various doping levels (2001)
Sutar, Dayanand, Mithra, Madan, Menon, Reghu, Subramanyam, SV
The temperature dependence of dc conductivity (from 1.5 to 300 K), and magnetoresistance (up to 7T) have been studied on polypyrrole samples doped with $PF^-_6(PPy - PF_6)$ at various doping levels....
Mithra, Madan LM, Cao, Y, Cho, Shinuk, Sutar, Dayanand, Lee, K, Menon, Reghu, ...
We discuss the disorder induced metal-insulator transition in polypyrrole doped with $CF_3SO_3^-$ in an attempt to understand the electrical transport in the vicinity of the transition. With the...
Conductivity and magnetoresistance in polypyrrole-$PF_6$ at various doping levels (2001)
Sutar, Dayanand, Mithra, Madan, Menon, Reghu, Subramanyam, SV
The temperature dependence of dc conductivity (from 1.5 to 300 K), and magnetoresistance (up to 7T) have been studied on polypyrrole samples doped with $PF^-_6(PPy - PF_6)$ at various doping levels....
Enhancement of magnetoresistance in manganite multilayers (2000)
Venlmadhav, A, Hegde, MS, Prasad, V, Subramanyam, SV
Manganite multilayers have been fabricated using $La_{0.67}$$Ca_{0.33}$$MnO_3$ as the ferromagnetic layer and $Pr_{0.7}$$Ca_{0.3}$$MnO_3$ and $Nd_{0.5}$$Ca_{0.5}$$MnO_3$ as the spacer layers. All the...
Annealing effect on transport properties of $Nd_{0.67}Sr_{0.33}MnO_{3}$ thin films (2000)
Pattabiraman, M, Murugaraj, P, Rangarajan, G, Prasad, V, Subramanyam, SV, Sastry, VS, ...
Annealing dependence of the lattice parameter, resistivity, magnetoresistance and thermopower have been studied on $Nd_{0.67}Sr_{0.33}MnO_{3}$ thin films deposited on $LaAlO_{3}$ and alumina...
Transport and magneto-transport study on some conducting polyanilines (2000)
Angappane, S, Srinivasan, D, Rangarajan, G, Prasad, V, Subramanyam, SV, Wessling, B
The room temperature electrical conductivities of pristine polyaniline (PAni), its blend with PMMA (polymethylmethacrylate) in the ratio 2 : 3 and PAni extracted from the blend were found to be 18,...
$ALaMnBO_6$ (A = Ca, Sr, Ba; B = Fe, Ru)double perovskites (2000)
Ramesha, K, Thangadurai, V, Sutar, D, Subramanyam, SV, Subbanna, GN, Gopalakrishnan, J
We report the synthesis and investigation of electrical and magnetic properties of double perovskites of the formula $ALaMnBO_6$ for A = Ca, Sr, Ba and B = Fe, Ru. Powder X-ray diffraction (XRD)...
The influence of disorder on the electrical properties (DC conductivity and magnetoresistance) of amorphous conducting carbon films, prepared by the pyrolysis of tetrachlorophthalic anhydride, is...
Annealing effect on transport properties of $Nd_{0.67}Sr_{0.33}MnO_{3}$ thin films (2000)
Pattabiraman, M, Murugaraj, P, Rangarajan, G, Prasad, V, Subramanyam, SV, Sastry, VS, ...
Annealing dependence of the lattice parameter, resistivity, magnetoresistance and thermopower have been studied on $Nd_{0.67}Sr_{0.33}MnO_{3}$ thin films deposited on $LaAlO_{3}$ and alumina...
Enhancement of magnetoresistance in manganite multilayers (2000)
Venlmadhav, A, Hegde, MS, Prasad, V, Subramanyam, SV
Manganite multilayers have been fabricated using $La_{0.67}$$Ca_{0.33}$$MnO_3$ as the ferromagnetic layer and $Pr_{0.7}$$Ca_{0.3}$$MnO_3$ and $Nd_{0.5}$$Ca_{0.5}$$MnO_3$ as the spacer layers. All the...
$ALaMnBO_6$ (A = Ca, Sr, Ba; B = Fe, Ru)double perovskites (2000)
Ramesha, K, Thangadurai, V, Sutar, D, Subramanyam, SV, Subbanna, GN, Gopalakrishnan, J
We report the synthesis and investigation of electrical and magnetic properties of double perovskites of the formula $ALaMnBO_6$ for A = Ca, Sr, Ba and B = Fe, Ru. Powder X-ray diffraction (XRD)...
Transport and magneto-transport study on some conducting polyanilines (2000)
Angappane, S, Srinivasan, D, Rangarajan, G, Prasad, V, Subramanyam, SV, Wessling, B
The room temperature electrical conductivities of pristine polyaniline (PAni), its blend with PMMA (polymethylmethacrylate) in the ratio 2 : 3 and PAni extracted from the blend were found to be 18,...
Sahana, M, Hegde, MS, Shivakumara, C, Prasad, V, Subramanyam, SV
Electrical and magnetic properties of $La_{0.82}K_{0.08}MnO_{3-\delta}$, both in polycrystalline and thin film forms, have been examined in the temperature range 1.2 to 300 K. Near the...
Sahana, M, Hegde, MS, Shivakumara, C, Prasad, V, Subramanyam, SV
Electrical and magnetic properties of $La_{0.82}K_{0.08}MnO_{3-\delta}$, both in polycrystalline and thin film forms, have been examined in the temperature range 1.2 to 300 K. Near the...
The influence of disorder on the electrical properties (DC conductivity and magnetoresistance) of amorphous conducting carbon films, prepared by the pyrolysis of tetrachlorophthalic anhydride, is...