N. Gayathri

Publication List Details

Period

1900 - 2008

Number

36

Co-Authors

Tuning wetting by tailoring surface morphology (2008)

Sarkar, S., Patra, S., Gayathri, N., Banerjee, S.

The relation between the contact angle of a liquid drop and the morphological parameters of the solid surface have been investigated. We show experimentally that the wetting property of a solid...

Lattice Resistance to Dislocation Motion at the Nanoscale (2008)

Dutta, A., Bhattacharya, M., Barat, P., Mukherjee, P., Gayathri, N., Das, G. C.

In this letter we propose a model that demonstrates the effect of free surface on the lattice resistance experienced by a moving dislocation in nanodimensional systems. This effect manifests in an...

Character of the Dislocation Bands in the (A+B) regime of the Portevin-Le Chatelier effect in Al-2.5%Mg alloy (2008)

Chatterjee, A., Sarkar, A., Barat, P., Mukherjee, P., Gayathri, N.

The Portevin-Le Chatelier(PLC) effect has been investigated by deforming Al-2.5%Mg alloy in the strain rate regime where simultaneously two types (type B and type A) of serrations appear in the...

Markov Property of Continuous Dislocation Band Propagation (2008)

Chatterjee, A., Sarkar, A., Bhattacharya, Sourav, Mukherjee, P., Gayathri, N., Barat, P.

Tensile tests were carried out by deforming polycrystalline samples of substitutional Al-2.5%Mg alloy at room temperature for a range of strain rates. The Portevin-Le Chatelier (PLC) effect was...

Change in the room temperature magnetic property of ZnO upon Mn doping (2007)

Banerjee, S., Rajendran, K., Gayathri, N., Sardar, M., Senthilkumar, S., Sengodan, V.

We present in this paper the changes in the room temperature magnetic property of ZnO on Mn doping prepared using solvo-thermal process. The zero field cooled (ZFC) and field cooled (FC)...

Enhancement of ferromagnetism upon thermal annealing in pure ZnO (2007)

Banerjee, S., Mandal, M., Gayathri, N., Sardar, M.

We report here enhancement of ferromagnetism in pure ZnO upon thermal annealing with the ferromagnetic transition temperature Tc above room temperature. We observe a finite coercive field upto 300K...

Bulk ferromagnetism and large changes in photoluminescence intensity by magnetic field in $\beta$-Ga$_2$O$_3$ (2007)

Sridharan, V., Banerjee, Sangam, Sardar, Manas, Dhara, Sandip, Gayathri, N., Sastry, V. S.

In this letter we report observation of room temperature ferromagnetism in bulk Ga$_2$O$_3$ . We also observe large (10-60%) increase/decrease in photoluminescence. In the red(700 nm...

Enhanced thermopower upon Ni substitution in Na0.75CoO2 (2005)

Gayathri, N., Bharathi, A., Hariharan, Y.

Thermopower measurements have been carried out on the Ni substituted samples of Na0.75CoO2 in the temperature range 4.2K to 300K. The room temperature TEP increases by 20microV/K even with 1% Ni...

Detecting onset of chain scission and crosslinking of gamma-ray irradiated elastomer surfaces using frictional force microscopy (2005)

Banerjee, S., Sinha, N. K., Gayathri, N., Ponraju, D., Dash, S., Tyagi, A. K., ...

We report here that atomic force microscope (AFM) in frictional force mode can be used to detect onset of chain scission and crosslinking in polymeric and macromolecular samples upon irradiation. A...

Drastic ground state changes induced by Ni substitution in NaxCoO2 (2005)

Gayathri, N., Premila, M., Bharathi, A., Sastry, V. S., Sundar, C. S., Hariharan, Y.

We report on the effect of Ni substitution at the Co site on the physical properties of NaxCoO2 system by investigating the series NaxCo1-yNiyO2 (x=0.75, 0

Raman Scattering Investigation of Electron Phonon Coupling in Carbon substituted MgB2 (2005)

Sakuntala, T., Bharathi, A., Deb, S. K., Gayathri, N., Sundar, C. S., Hariharan, Y.

Room temperature Raman scattering measurements have been carried out on well characterized samples of MgB2-xCx. The Raman line corresponding to the E2g phonon mode shows progressive hardening from...

Conductivity landscape of highly oriented pyrolytic graphite surface containing ribbons and edges (2005)

Banerjee, S., Sardar, M., Gayathri, N., Tyagi, A. K., Raj, Baldev

We present an extensive study on electrical spectroscopy of graphene ribbons and edges of highly oriented pyrolytic graphite (HOPG) using atomic force microscope (AFM). We have addressed in the...

Point contract spectroscopy and temperature dependence of resistivity of metallic Sodium Tungsten Bronzes - Role of optical phonons (2004)

Gayathri, N, Raychaudhuri, AK

In this paper we report the results of electrical resistivity $(1.5\leq T \leq 300K)$ and point contact spectroscopy (PCS) measurements on single crystals of metallic sodium tungsten bronze with...

Mapping of surface local elastic constant using Atomic Force Acoustic Microscopy (2004)

Banerjee, S., Gayathri, N., Shannigrahi, S. R., Dash, S., Tyagi, A. K., Raj, B.

We report a systematic study to determine local elastic properties of surfaces combining atomic force microscope (AFM) with acoustic waves which is known as atomic force acoustic microscopy - AFAM....

Point contract spectroscopy and temperature dependence of resistivity of metallic Sodium Tungsten Bronzes - Role of optical phonons (2004)

Gayathri, N, Raychaudhuri, AK

In this paper we report the results of electrical resistivity $(1.5\leq T \leq 300K)$ and point contact spectroscopy (PCS) measurements on single crystals of metallic sodium tungsten bronze with...

Point-contact spectroscopy of single crystal $La_0_._75Sr_0_._2_5MnO_3$ and resistivity due to electron-phonon interaction (2002)

Mitra, J, Raychaudhuri, AK, Gayathri, N, Mukovskii, Ya M

In this paper we report point-contact spectroscopy (PCS) measurements on single crystals of metallic $La_0_._75Sr_0_._2_5MnO_3$. The electron-phonon coupling function as obtained from the PCS shows...

Point-contact spectroscopy of single crystal $La_0_._75Sr_0_._2_5MnO_3$ and resistivity due to electron-phonon interaction (2002)

Mitra, J, Raychaudhuri, AK, Gayathri, N, Mukovskii, Ya M

In this paper we report point-contact spectroscopy (PCS) measurements on single crystals of metallic $La_0_._75Sr_0_._2_5MnO_3$. The electron-phonon coupling function as obtained from the PCS shows...

Computer simulation study of the subquadratic quantum number dependence of vibrational overtone dephasing: Comparison with the mode-coupling theory predictions (1999)

Gayathri, N, Bagchi, Biman

Experimental studies have demonstrated that the vibrational dephasing of overtones do not always follow the quadratic quantum number ~n! dependence predicted by the Kubo Oxtoby theory of vibrational...

Computer simulation study of the subquadratic quantum number dependence of vibrational overtone dephasing: Comparison with the mode-coupling theory predictions (1999)

Gayathri, N, Bagchi, Biman

Experimental studies have demonstrated that the vibrational dephasing of overtones do not always follow the quadratic quantum number ~n! dependence predicted by the Kubo Oxtoby theory of vibrational...

Magnetoresistance of metallic perovskite oxide LaNiO$_{3-\delta}$ (1998)

Gayathri, N., Raychaudhuri, A. K., Xu, X. Q., Peng, J. L., Greene, R. L.

We report a study of the magnetoresistance (MR) of the metallic perovskite oxide LaNiO$_{3-\delta}$ as a function of the oxygen stoichiometry $\delta$ ($\delta \leq$ 0.14), magnetic field (H $\leq...

The nature of the charge-ordered state in $Y_{0.5}Ca_{0.5}MnO_3$ with a very small average radius of the A-site cations (1998)

Arulraj, Anthony, Gundakaram, R, Biswas, Amlan, Gayathri, N, Raychaudhuri, AK, Rao, CNR

A detailed investigation of $Y_{0.5}Ca_0.5}MnO_3$ with a very small radius of the A-site cations $(\langle r_A \rangle \approx 1.13 \AA)$ reveals the occurrence of a charge- ordering transition in...

The nature of the charge-ordered state in $Y_{0.5}Ca_{0.5}MnO_3$ with a very small average radius of the A-site cations (1998)

Arulraj, Anthony, Gundakaram, R, Biswas, Amlan, Gayathri, N, Raychaudhuri, AK, Rao, CNR

A detailed investigation of $Y_{0.5}Ca_0.5}MnO_3$ with a very small radius of the A-site cations $(\langle r_A \rangle \approx 1.13 \AA)$ reveals the occurrence of a charge- ordering transition in...

Electrical transport, magnetism, and magnetoresistance in ferromagnetic oxides with mixed exchange interactions: A study of the $La_{0.7}Ca_{0.3}Mn_{1-x}Co_xO_3$ system (1997)

Gayathri, N, Raychaudhuri, AK, Tiwary, SK

In this paper we report the results of an extensive investigation of the $La_{0.7}Ca_{0.3}Mn_{1-x}Co_xO_3$ system. Substitution of Mn by Co dilutes the double-exchange (DE) mechanism and changes the...

Electrical transport, magnetism, and magnetoresistance in ferromagnetic oxides with mixed exchange interactions: A study of the $La_{0.7}Ca_{0.3}Mn_{1-x}Co_xO_3$ system (1997)

Gayathri, N, Raychaudhuri, AK, Tiwary, SK

In this paper we report the results of an extensive investigation of the $La_{0.7}Ca_{0.3}Mn_{1-x}Co_xO_3$ system. Substitution of Mn by Co dilutes the double-exchange (DE) mechanism and changes the...

Effect of Substitution of $Cr^{3+}$ in Place of $Mn^{3+}$ in Rare-Earth Manganates on the Magnetism and Magnetoresistance: Role of Superexchange Interaction and Lattice Distortion in $LnMn_{1-x}Cr_xO_3$ (1996)

Gundakaram, R, Arulraj, Anthony, Vanitha, PV, Rao, CNR, Gayathri, N, Raychaudhuri, AK, ...

Magnetic and electrical properties of oxides of the formula $LnMn_{1-x}Cr_xO_3$ (Ln= rare earth) have been investigated to understand the importance of the $Mn^{3+}-O-Cr^{3+}$ superexchange...

Effect of Substitution of $Cr^{3+}$ in Place of $Mn^{3+}$ in Rare-Earth Manganates on the Magnetism and Magnetoresistance: Role of Superexchange Interaction and Lattice Distortion in $LnMn_{1-x}Cr_xO_3$ (1996)

Gundakaram, R, Arulraj, Anthony, Vanitha, PV, Rao, CNR, Gayathri, N, Raychaudhuri, AK, ...

Magnetic and electrical properties of oxides of the formula $LnMn_{1-x}Cr_xO_3$ (Ln= rare earth) have been investigated to understand the importance of the $Mn^{3+}-O-Cr^{3+}$ superexchange...