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Full-Text Articles in Physics
Effect Of Zinc Incorporation On The Density Of Defect States In A-Se_{85}Te_{15} Glassy Alloy, Shikha Shukla, Santosh Kumar
Effect Of Zinc Incorporation On The Density Of Defect States In A-Se_{85}Te_{15} Glassy Alloy, Shikha Shukla, Santosh Kumar
Turkish Journal of Physics
Present work incorporates the study of d.c. conductivity measurements at high electric fields in vacuum evaporated thin films of Se_{85-x}Te_{15}Zn_x (x = 0, 2, 4, 6 and 10) glassy alloys. Current-Voltage (I-V) characteristics have been measured at various fixed temperatures. In these samples, at low electric fields, ohmic behavior is observed. However, at high electric fields (E \sim 10^4 V/cm), non ohmic behavior is observed. An analysis of the experimental data confirms the presence of space charge limited conduction (SCLC) in the glassy materials studied in the present case. From the fitting of the data to the theory of SCLC, …
Role Of Metallic Zn And In Additives In The Electrical And Dielectric Properties Of Se_{0.85}Te_{0.15} Glassy Alloy, Jyoti Sharma, Santosh Kumar
Role Of Metallic Zn And In Additives In The Electrical And Dielectric Properties Of Se_{0.85}Te_{0.15} Glassy Alloy, Jyoti Sharma, Santosh Kumar
Turkish Journal of Physics
In this paper we report the effect of metallic Zn and In additives on the electrical and dielectric properties of Se_{0.85}Te_{0.15} glassy system. The temperature and frequency dependence of the dielectric parameters in glassy Se_{0.85}Te_{0.15}, Se_{0.75}Te_{0.15}In_{0.10} and Se_{0.75}Te_{0.15}Zn_{0.10} alloys are studied by measuring capacitance and dissipation factor in the frequency range (1 kHz--5 MHz) and temperature range (300--350 K). Direct current (dc) measurements were also performed in the aforesaid temperature range to assess the dc conduction losses. Results are interpreted in terms of a theoretical model which is based on two electron hopping over a potential barrier and is applicable …
Composition Dependent Of Dielectric Properties In Se_{100-X}Pb_X Glassy Alloys, Jyoti Sharma, Santosh Kumar
Composition Dependent Of Dielectric Properties In Se_{100-X}Pb_X Glassy Alloys, Jyoti Sharma, Santosh Kumar
Turkish Journal of Physics
In this paper we report the composition dependent of dielectric properties in Se_{100-x}Pb_x (x = 0, 2, 4, 6 and 10) glassy alloys. The temperature and frequency dependence of the dielectric constants and the dielectric losses in the above glassy systems in the frequency range 1 kHz-5 MHz and temperature range 300-340 K have been measured. It has been found that dielectric constant and the dielectric loss both are highly dependent on frequency and temperature and also found to be increased with increasing concentration of Pb in pure amorphous Se. The results have been interpreted in terms of increase in …
High Field Conduction In Thin Films Of A-(Ge_{.20}{Se0}_{.80})_{1-X}{Pb}_X Glassy Alloys, Rachna Singh, Santosh Kumar
High Field Conduction In Thin Films Of A-(Ge_{.20}{Se0}_{.80})_{1-X}{Pb}_X Glassy Alloys, Rachna Singh, Santosh Kumar
Turkish Journal of Physics
The present paper reports d.c. conductivity measurements at high electric fields in vacuum evaporated amorphous thin films of (Ge_{.20}Se0_{.80})_{1-x}Pb_x (where x = 0, 0.02, 0.04, 0.06 and 0.10) glassy alloys. Current-Voltage (I-V) Characteristics have been measured at various fixed temperatures. In these samples, at low electric fields, ohmic behavior is observed. However, at high electric fields (E \sim 10^4 V/cm), non-ohmic behavior is observed. An analysis of the experimental data confirms the presence of space charge limited conduction (SCLC) in the glassy materials studied in the present case. From the fitting of the data to the theory of SCLC, the …
Role Of Sn In The Density Of Defect States In A-Se_{0.75}Te_{0.25} And A-Se_{0.85}Te_{0.15}Thin Films, N. Sharma, Santosh Kumar
Role Of Sn In The Density Of Defect States In A-Se_{0.75}Te_{0.25} And A-Se_{0.85}Te_{0.15}Thin Films, N. Sharma, Santosh Kumar
Turkish Journal of Physics
In this paper we report the effect of Sn incorporation in the density of defect states of two binary Se-Te glassy systems, comparing the properties of a-Se_{0.75}Te_{0.25}, a-Se_{0.85}Te_{0.15} and a-Se_{0.75}Te_{0.15}Sn_{0.10} glassy alloys. Properties of d.c. conductivity at high electric fields in vacuum were examined; and current-voltage (I-V) characteristics have been measured at various fixed temperatures. Ohmic behavior is observed at low electric fields; while at high electric fields (E \sim 10^4 V/cm), non-ohmic behavior is observed. An analysis of the experimental data confirms the presence of space charge limited conduction (SCLC) in the studied glassy materials. Density of defect states …
Dielectric Relaxation In Glassy Se_{100 - X} Sb_X, N. Choudhary, A. Kumar
Dielectric Relaxation In Glassy Se_{100 - X} Sb_X, N. Choudhary, A. Kumar
Turkish Journal of Physics
Frequency and temperature dependence of dielectric constant \varepsilon' and dielectric loss \varepsilon'' are studied in glassy Se_{1-x} Sb_x (x = 0, 0.02, 0.04, 0.06, 0.08 and 0.10) in the frequency range from 1--10 kHz and in the temperature range 290 K to 360 K. The experimental results indicate that no dielectric dispersion exist in glassy Se in the operating range of frequencies. However, when Sb concentration increases in Se_{1-x} Sb_x (x = 0.02, 0.04, 0.06, 0.08 and 0.10) dielectric dispersion starts in the upper frequency and temperature range. The values of \varepsilon' and \varepsilon'', as functions of temperature and frequency, …
Calorimetric Studies On Se_{0.68}Ge_{0.22}M_{0.10} (M = Cd, In, Pb) Chalcogenide Glasses, N. Mehta, P. Agarwal, A. Kumar
Calorimetric Studies On Se_{0.68}Ge_{0.22}M_{0.10} (M = Cd, In, Pb) Chalcogenide Glasses, N. Mehta, P. Agarwal, A. Kumar
Turkish Journal of Physics
Differential scanning calorimetry (DSC) is performed at different heating rates under non-isothermal conditions to calculate the activation energy of crystallization E_c for chalcogenide glasses Se_{0.68}Ge_{0.22}M_{0.10} (M = Cd, In and Pb) using the well known Kissinger's relation, Matusita-Sakka theory and the method of Augis-Bennett. The overall mean bond energy of these glassy alloys has been evaluated using theory of Tichy and Ticha. A good correlation has been found between E_c and . This indicates that the overall mean bond energy plays an important role in the thermal crystallization of chalcogenide glasses.
Study Of Density Of Localized States In A-Se_{100 - X}Sb_X Films By Space Charge Limited Conduction Measurements, V. S. Kushwaha, Santosh Kumar, A. Kumar
Study Of Density Of Localized States In A-Se_{100 - X}Sb_X Films By Space Charge Limited Conduction Measurements, V. S. Kushwaha, Santosh Kumar, A. Kumar
Turkish Journal of Physics
The present paper reports dc conductivity measurements at high electric fields in vacuum evaporated a-Se_{1 - x}Sb_x (x = 0, 0.02, 0.04, 0.06) thin films. At high fields (~ 10^4 V .cm^{-1}), current can be modelled by the theory of space charge-limited conduction in the case of uniform distribution of localised states in the mobility gap of these materials. The addition of Sb in Se results in an increase in the density of localised states.
Calorimetric Studies Of The Crystallization Growth Process In Glassy Se_{70}Te_{30-X}Ag_X Alloys, N. Mehta, D. Kumar, A. Kumar
Calorimetric Studies Of The Crystallization Growth Process In Glassy Se_{70}Te_{30-X}Ag_X Alloys, N. Mehta, D. Kumar, A. Kumar
Turkish Journal of Physics
Differential Scanning Calorimetry (DSC) is performed at different heating rates under non-isothermal conditions to study the crystallization kinetics of Se_{.70}Te_{.26}Ag_{.04} and Se_{.70}Te_{.24}Ag_{.06} chalcogenide glasses in terms of the activation energy of nucleation and growth process. To understand the nucleation and growth process, the values of the growth morphology parameter n and the numerical factor m of crystallization mechanism have been evaluated using different non--isothermal methods. The values of n and m have been found to be nearly equal, indicating that the present glasses have sufficient nuclei before DSC experiment and the activation energy for nucleation process E_N is zero. Hence, …