Université de Fribourg

Effect of combined addition of graphene oxide and citric acid on superconducting properties of MgB₂Effect of combined addition of graphene oxide and citric acid on superconducting properties of MgB₂

Sudesh ; Das, Saikat ; Bernhard, Christian ; Varma, G. D.

In: Physica C: Superconductivity and its Applications, 2015, vol. 509, p. 49–55

In the present work, polycrystalline samples with compositions MgB₂ + 3wt% GO + x wt% C₆H₈O₇ (x = 0, 5 and 10) have been synthesized to study the effect of combined addition of graphene oxide (GO) and citric acid (C₆H₈O₇) on superconducting properties of MgB₂. X-ray diffraction studies show the formation of hexagonal crystal structure of MgB₂ with space...

Université de Fribourg

Enhanced superconducting properties of rare-earth oxides and graphene oxide added MgB₂

Sudesh ; Das, S. ; Bernhard, Christian ; Varma, G.D.

In: Physica C: Superconductivity, 2014, vol. 505, p. 32–38

In this paper, the effects of addition of (i) graphene oxide (GO), (ii) a series of rare-earth (RE, RE = La, Sm, Eu, Gd, Tb and Ho) oxides (REO) and (iii) a mixture of GO and rare-earth oxides (GO + REO) on the superconducting properties of MgB₂, have been studied with the help of electrical transport and magnetic measurements. All the samples have been prepared following the standard...

Université de Fribourg

Effect of graphene oxide doping on superconducting properties of bulk MgB2

Sudesh, Sharma ; Kumar, N. ; Das, Saikat ; Bernhard, Christian ; Varma, G. D.

In: Superconductor Science and Technology, 2013, vol. 26, no. 9, p. 095008

In the present paper we report the effect of graphene oxide (GO) doping on the structural and superconducting properties of MgB₂. Bulk polycrystalline samples have been synthesized via a solid state reaction route with compositions MgB₂ + x wt% of GO (x = 0, 1, 2, 3, 5, 7 and 10) by sintering at ~850 ° C in a reducing atmosphere of Ar/H₂ (9:1). The x-ray diffraction...

Université de Fribourg

Effect of Fe composition on the superconducting properties (Tc, Hc2 and Hirr) of FexSe1/2Te1/2 (x = 0.95, 1.00, 1.05 and 1.10)

Sudesh ; Rani, S. ; Das, S. ; Rawat, R. ; Bernhard, Christian ; Varma, G. D.

In: Journal of Applied Physics, 2012, vol. 111, no. 7, p. E119

In the present work, we have studied the effect of Fe composition on the superconducting properties, such as transition temperature (Tc), upper critical field (Hc2), and irreversibility field (Hirr) of FeSe1/2Te1/2. The polycrystalline samples have been prepared via solid state reaction...

Université de Fribourg

DC magnetization investigations in Ti1−xMnxO₂ nanocrystalline powder

Sharma, Sudesh ; Chaudhary, Sujeet ; Kashyap, Subhash C. ; Malik, Vivek K.

In: Journal of Alloys and Compounds, 2011, vol. 509, no. 27, p. 7434-7438

In the present paper, DC magnetization investigation on the insulating nanocrystalline powder samples of Ti1−xMnxO₂ (x = 0, 0.05, 0.10, and 0.15) prepared by simple chemical route is reported. Structural measurements revealed phase pure anatase structure of TiO₂ when x ≤ 0.05 and a mixture of anatase and rutile TiO₂ along with the...