Rashmi Singh; Puneet Jain; Naresh Kumar; Pramod Kumar
Abstract
Thin films of Co2MnSi are grown on n-doped Si (100) and SiO2 (100) substrates by RF sputtering. The deposition time to grow the films is varied, once for ten minutes and another for an hour at a particular substrate temperature 600oC and keeping all the other parameters same. The Co2MnSi thin films deposited ...
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Thin films of Co2MnSi are grown on n-doped Si (100) and SiO2 (100) substrates by RF sputtering. The deposition time to grow the films is varied, once for ten minutes and another for an hour at a particular substrate temperature 600oC and keeping all the other parameters same. The Co2MnSi thin films deposited on Si and SiO2 are crystalline irrespective of the deposition time. The grains were round in the thin films deposited for 10 minutes and these grains are more consistently interconnected in the films deposited for 1 hour. This is supported by the surface roughness data from AFM. The rms roughness is found to be 4.82nm for Si for 10 minutes and 2.50nm for Si for 1 hour deposition that was observed over an area of 3µm2. Copyright © 2017 VBRI Press.
Pramod Kumar; Rashmi Singh; Faizan Ahmad; Chandra Shekhar; Naresh Kumar; Rachana Kumar
Abstract
A proximity-induced superconductivity is used in a single crystal flake Bi2Te3 topological insulator to probe the behavior of magnetoresistance around the local superconducting critical fields. The magnetoresistance in Bi2Te3 and GaAs materials with superconducting contacts are studied and compared. ...
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A proximity-induced superconductivity is used in a single crystal flake Bi2Te3 topological insulator to probe the behavior of magnetoresistance around the local superconducting critical fields. The magnetoresistance in Bi2Te3 and GaAs materials with superconducting contacts are studied and compared. A contradictory behavior in both of the systems is observed (A positive resistance correction was observed in GaAs, whereas a negative resistance correction was observed in Bi2Te3). For Bi2Te3, periodic oscillations are observed in the dR/d|B| verses B plots. These periodic oscillations originate from a coexistence of proximity-induced superconductivity with a normal linear region created either by temperature or applied magnetic field. At high magnetic fields (> 2T) and low temperatures (1.5K), Shubnikov de Hass oscillations are also observed. Copyright © 2016 VBRI Press