助教
ジャー.アロク.クマール
Superconductivity is very interesting subject from the point of view of both fundamental Physics and applied research. The technogolical advances in this area can bring revolution in the area of electric power transmission.
The lossless transmission of electrical currents in superconductors is very often regarded as ‘energy superhighway’ with greatly enhanced efficiency. By manipulating the microstructure of the superconducting materials, the current carrying capacity can be significantly enhanced even at higher applied magnetic field. These superconducting materials can carry electrical currents more than 100 times larger than their conventional counterparts with minimum loss of energy. The increased efficiency of superconductive electric power products may result in greatly reduced carbon emission resulting from using the conventional alternatives.
超電導は、基礎物理、応用物理学 両側面から非常に興味深いテーマです。この分野が発展すれば電力輸送に革新を起こすことができます。
Development of superconducting coated conductors
超伝導体被覆導体の研究
Superconducting thin films
超電導薄膜
Superconductivity, Thin films, Microstructure control, Critical current properties
超電導、薄膜、微細加工、臨海電流
Our current research activities are focused on enhancement of vortex pinning properties of REBa2Cu3O7-x(REBCO) thin films particularly at liquid nitrogen temperature (77 K). However, there are many areas of applications which require superconducting films with strong vortex pinning characteristics at lower temperatures. The pinning performance of REBCO films with hybrid pinning centers are being investigated at present. The coherence length of REBCO decreases at low temperature and hence small pinning centers are desired for enhanced vortex pinning strength of superconducting thin films. The geometry and density of APCs (artificial pinning centers) need to be controlled for enhanced critical current density particularly at low temperatures. The variation of superconducting matrix is also being investigated where YBCO is replaced by GdBCO, a higher Tc (superconducting critical temperature) material. Also, the anisotropy in the critical current density is a challenging issue to address. Although, the isotropic enhancement is observed at 77 K and 65 K, it needs to be investigated if these APCs are effective enough at lower temperatures.
電力輸送に革新を超すことのできる超電導技術の研究をしています。超伝導体に抵抗ゼロで流すことのできる最大の電流値のことを臨界電流密度と呼びますが、磁束のピンニング効果を増幅させることでこの臨界電流密度を増加させることができると期待されます。 現在REBCOを対象にこのピンニングパフォーマンスを向上させるための研究を行っています。
Apart from working in the area of superconductivity, I want to start research activities in the area of multiferroic thin films. Multiferroic materials are very interesting due to the prospect of controlling charges by applied magnetic fields and spins by applied voltages, which can be used to construct new forms of multifunctional devices and sensors.
Pulsed Laser Deposition (PLD) system, X-ray diffraction (XRD) system, Physical properties measurement system (PPMS).
Junior research fellowship (JRF) and then Senior research fellowship from CSIR, New Delhi, India during Ph. D. program. University topper (1st rank) in Masters degree program.
1. Isotropic enhancement in the critical current density of YBCO thin films incorporating nanoscale Y2BaCuO5 inclusions
A. K. Jha et al., Journal of Applied Physics, 122, 093905 (2017)
2. Controlling the critical current anisotropy of YBCO superconducting films by incorporating hybrid artificial pinning centers
A. K. Jha et al., IEEE Trans. Appl. Supercond., 26, 2525989 (2016)
3. Tailoring the vortex pinning strength of YBCO thin films by systematic incorporation of hybrid artificial pinning centers
A. K. Jha et al., Superconductor Science and Technology, 28, 114004 (2015)
4. Tuning the microstructure and vortex pinning properties of YBCO based superconducting nanocomposite films by controlling the target rotation speed
A. K. Jha et al., Superconductor Science and Technology, 27, 025009 (2014).
