Research Extension:

Research experience

[1] Polycrystalline sample preperation mainly HTSC, CMR, spinel oxides, II-VI semiconductors.

[2]  Preperation of nanophase materials by ball-milling and chemical process. 

[3] Experience of developing Positron lifetime measurement set-up with very low time resolution (185 ps). 

[4] Experience of setting up Coincidence Doppler broadening set up in the Calcutta University Positron Laboratory. 

[5] Experience on low temperature experiments (30 K) of resistivity, Positron and Mossbauer spectroscopy.

[6] Participated in five beam time experiments at pelletron accelarator at NSC, New   Delhi.

[7] Participated in one beam time experiment at cyclotron accelerator at VECC, Kolkata.

[8] Participated in one beam time experiment (Compton scattering expt.) at ESRF, Grenoble, France.

[9] Experience in experiments with positron beam (positron scattering experiment with molecular gases) at Trento, Italy.

[10] Knowledge on optical absorption measurement and analysis.

[11] DFT calculation by VASP.

[12] Growth and characterization of ZnO nanowires.  

Teaching Experience:

Under Graduate Physics Both Honours And General Courses                 

Awards:

Awarded CSIR (Govt. of India), JRF (NET) on December 11, 1996

Professional Membership:

Indian Physical Society

Important Publication:

Research Papers (Int.)	48 (Forty eight)
National Journal/Proc.	03 (three)
Reports   1
Books 1    In preparation 2
Total citations ~ 800      h index 16

Click here to get details of Publications List

(A) On high temperature superconducting (HTSC) materials

[1] Enhancement and degradation of T_c in Bi-HTSC due to Li³⁺ irradiations, A. Sarkar, Udayan De, D. Sanyal, Ravi Kumar and D. Banerjee, Nucl. Instru. & Meth. B 156 (1999) 50.

[2] Probing single crystalline Bi₂Sr_­2CaCu₂O_8+d by positron annihilation spectroscopy, M. Chakraborti, A. Sarkar, S. Chattopadhayay, D. Sanyal, R. Bhattacharya, A. K. Pradhan and D. Banerjee,  Solid State Commun. 128 (2003) 321.

[3] Studies of coincidence Doppler broadening of the electron-positron annihilation radiation in the single crystalline Bi₂Sr_­2CaCu₂O_8+d superconductor, M. Chakraborti, A. Sarkar, D. Sanyal, G.P. Karwasz and A. Zecca, Phys. Lett. A 321 (2004) 376.

[4] Doppler broadening of the electron-positron annihilation radiation in La-Y-Ca-Ba-Cu-O superconductor, Mahuya Chakraborti, K.R. Mavani, S. Chattopadhayay, A. Sarkar and D. Sanyal, Phys. Lett. A 329 (2004) 231.

[5] Doppler broadening measurements of positron annihilation in single crystalline  Bi₂Sr_­2CaCu₂O_8+d  high T_c superconductor along two different crystallographic directions, Mahua Chakraborti, S. Chattopadhayay, A. Sarkar, D. Sanyal and A. Chakraborti, Physica C  416 (2004) 25.

[6] Interesting aspects of the analysis of resistivity in Li³⁺ irradiated Bi-2212, A. Sarkar, S. Chattopadhyay, Ravi Kumar and Udayan De, Nucl. Instru. & Meth. B 230 (2005) 284.

[7] Unusual metal-like state in HTSC and CMR oxides, S. Chattopadhyay, Ravi Kumar and A. Sarkar, Nucl. Instru. & Meth. B 244 (2006) 132.

(B) On colossal magnetoresistive (CMR) manganites

[1] Positron annihilation studies on La_(1-x)Pb_xMnO₃ system, A. Banerjee, B.K. Chaudhuri, A. Sarkar, D. Sanyal, and D. Banerjee, Physica B 299 (2001) 130.

[2] Positron annihilation lifetime studies on La_0.5Pb_0.5Mn_1-yCr_yO₃, A. Banerjee, A. Sarkar, D. Sanyal, P. Chatterjee, D. Banerjee and B.K. Chaudhuri, Solid State Commun. 125 (2003) 65.

[3] Study of 50 MeV Li³⁺ irradiation induced changes in La_0.7Pb_0.3MnO₃, S. Chattopadhyay, A. Banerjee, A. Sarkar, Ravi Kumar, B.K. Chaudhuri and D. Banerjee, Radiation Meas. 36 (2003) 689.

[4]  Effect of Li³⁺ irradiation on the transport properties of La_0.7Pb_0.3MnO₃ type CMR material, S. Chattopadhyay, A. Sarkar, Aritra Banerjee, S. Karmakar, D. Banerjee,  Ravi Kumar and B.K. Chaudhuri, Nucl. Instr. & Meth. B 226 (2004) 274.

[5]  Radiation damage effects in CMR manganite materials, S. Chattopadhyay, Sudipto Pal, A. Sarkar, Ravi Kumar and B.K. Chaudhuri, Nucl. Instr. & Meth. B 230 (2005) 274.

[6] Studies of quenched disorder in La_0.7Ca_0.3MnO₃–type manganite system from magnetic, transport and positron annihilation spectroscopic measurements, S. Chattopadhyay, A. Sarkar, Sudipta Pal, S.D. Kulkarni, P.A. Joy, and B.K. Chaudhuri, Physica B 398 (2007) 23.   

(C) On II-VI and other semiconducting materials

[1] Electrical conductivity, thermo-electric power and and structure of differently heat-treated CdO, Udayan De, M.K. Chattopadhya, S. Chaudhury, A. Sarkar, D. Sanyal and T.K. Dey, J. Phys. & Chem. of Solids 61 (2000) 1955.  

[2] Resonance Scattering and RBS from non-stoichiometric Oxide, Udayan De, K.C. Verma, P. Karmakar, A. Sarkar, Soma Dey and Sikha Verma, Nucl. Instr. & Meth. B 212 (2003) 505.

[3] Grain size dependence of optical properties and positron annihilation parameters in Bi₂O₃ powder, Mahua Chakraborti, S. Chattopadhayay, A. Sarkar, D. Sanyal and A. Chakraborti, Nanotechnology 15 (2004) 1792.  

[4] Doppler broadening measurements of the electron-positron annihilation radiation in nanocrystalline ZrO₂, Mahua Chakraborti, D. Bhowmick, A. Sarkar, S. Chattopadhayay, S. DeChoudhury, D. Sanyal and A. Chakraborti, J. Mater. Sci. 40 (2005) 5265.  

[5] Defect dynamics in annealed ZnO by positron annihilation spectroscopy, Sreetama Dutta, Mahuya Chakraborti, S. Chattopadhyay, D. Jana, D. Sanyal, and A. Sarkar, J. Appl. Phys. 98 (2005) 053513.

[6] Annealing effect on nano-ZnO powder studied from positron lifetime and optical absorption spectroscopy, spectroscopy, Sreetama Dutta, S. Chattopadhyay, D. Jana, A. Banerjee, S. Manik, S.K. Pradhan, Manas Sutradhar, and A. Sarkar, J. Appl. Phys. 100 (2006) 114328.

[7] Defects and optical absorption in nanocrystalline ZnO, Sreetama Dutta, S. Chattopadhyay, Manas Sutradhar, A. Sarkar, Mahuya Chakraborti, D. Sanyal, D. Jana, J. Phys.: Condens. Matter 19 (2007) 236218.

[8] Role of defects in tailoring structural, electrical and optical properties of ZnO, Sreetama Dutta, S. Chattopadhyay, A. Sarkar, Mahuya Chakraborti, D. Sanyal, D. Jana, Prog. Mater. Sci. 54 (2009) 89.

[9] Synthesis and characterization of single phase Mn doped ZnO, S. Chattopadhyay, S. Dutta, A. Banerjee, D. Jana, S. Bandyopadhyay, S. Chattopadhyay and A. Sarkar, Physica B 404 (2009) 1509.

[10] A study on defect dynamics in annealed Si₃N₄ nanoparticles by positron annihilation spectroscopy, S. Chattopadhyay, S. Dutta, D. Jana, S. Chattopadhyay, D. Das, Mahuya Chakraborti, D. Sanyal and A. Sarkar, Physica Status Solidi C 6 (2009) 2533.

[11] Electrical resistivity peculiarities and positron lifetime in aneealed CdO, A. Sarkar, S. Chattopadhyay and Udayan De, Physica Status Solidi C 6 (2009) 2526.

[12] Interplay of defects in 1.2 MeV Ar irradiated ZnO, S. Chattopadhyay, S. Dutta, D. Jana, S. Chattopadhyay, A. Sarkar, P. Kumar, D. Kanjilal, D.K. Mishra and S.K. Ray, J. Appl. Phys. 107 (2010) 113516.

[13] Optical property modification of ZnO: Effect of 1.2 eV Ar irradiation, S. Chattopadhyay, S. Dutta, P. Pandit, D. Jana, S. Chattopadhyay, A. Sarkar, P. Kumar, D. Kanjilal, D.K. Mishra and S.K. Ray, Phys. Stat Sol. C 8 (2011) 512.

[14] Defect induced ferromagnetism in Mn doped ZnO, S. Chattopadhyay, S.K. Neogi, A. Sarkar, M.D. Mukadam, S.M. Yusuf, A. Banerjee, S. Bandopadhyay, J. Mag. Mag. Mater. 323 (2011) 363.

[15] Positron lifetime and photoluminesence investigation on single crystalline ZnO, A. Sarkar,  Mahuya Chakraborti, S. K. Ray, D. Bhowmick and D. Sanyal, J. Phys.: Condens. Matter 23 (2011) 155801.

[16] Effect of 50 MeV Li³⁺ irradiation on structural and electrical properties of Mn doped ZnO, S. K. Neogi, S. Chattopadhyay, Aritra Banerjee, S. Bandopadhyay, A. Sarkar, and Ravi Kumar, J. Phys.: Condens. Matter 23 (2011) 205801.

[17] Disorder driven optical processes in nanocrystalline ZnO, S. Chattopadhyay, S. K. Neogi, P. Pandit, S. Dutta, T. Rakshit, D. Jana, S. Chattopadhyay, A. Sarkar, and S.K. Ray, J. Lum. 132 (2012) 6.

[18] Probing Materials by Positron Annihilation Technique and Mossbauer Spectroscopy-Review, Mahuya Chakraborti, S. Chattopadhyay, D. Sanyal, A. Sarkar, D. Jana, Mater. Sci. Forum 699 (2012) 1.

[19] Photoluminescence and positron annihilation spectroscopic investigation on H⁺       irradiated ZnO single crystal, A. Sarkar,  Mahuya Chakraborti, D. Sanyal,D.Bhowmick,S.Dechoudhury, A. Chakrabarti, T. Rakshit and S.K. Ray, J. Phys.: Condens. Matter 24 (2012) 325503.

[20] Defects in 700 keV oxygen ion irradiated ZnO, S. Pal, A. Sarkar, S.Chattopadhyay, Mahuya Chakrabarti, D. Sanyal, P. Kumar, D. Kanjilal, T. Rakshit,S. K. Ray and D. Jana, Nucl. Instrum. & Meth. B 311 (2013) 20.

[21] Defects in 6 MeV H⁺ irradiated hydrothermal ZnO single crystal, A. Sarkar, M.Chakraborti, D. Bhowmick, A. Chakrabarti, S.K. Ray, D. Rafaja and D. Sanyal, J.Phys.: Condens. Matter 25 (2013) 385501.

[22] Zinc vacancy induced ferromagnetism in nanocrystalline ZnO, S. Ghose,A.Sarkar, S. Chattopadhyay, M. Chakraborti, D. Das, T. Rakshit, S.K. Ray and D.Jana, J. Appl. Phys. 114 (2013) 073516.

[23] Room temperature ferromagnetic ordering in 4 MeV Ar⁵⁺ irradiated rutile  

       TiO₂, D. Sanyal, M. Chakraborti, P. Nath, A. Sarkar, D. Bhowmick and A.Chakrabarti, J. Phys. D: Appl. Phys. 47 (2014) 025001.

[24] Defect driven ferromagnetism in SnO2: A combined study using Density functional theory and positron annihilation spectroscopy, A. Sarkar, D. Sanyal,P. Nath, M. Chakraborti, S. Pal, S. Chattopadhyay, D. Jana and K. Asokan, RSC Adv. 5 (2015) 1148.

[25] Native defects and optical properties of Ar ion irradiated ZnO, S. Pal, A. Sarkar,D Jana, P. Kumar, T. Rakshit and S. K. Ray, Adv. Mater. Lett.  6 (2015) 365.

[26] Low temperature photoluminescence from disordered granular ZnO, S. Pal,A.Sarkar, P. Kumar, D. Kanjilal, T. Rakshit, S. K. Ray and D. Jana, J. Lum. 169 (2016) 326. 

(D) On Positron-Molecule interaction

[1] Positron scattering from 3-hydroxy-tetrahydrofuran, Antonio Zecca, Luca Chiari, A. Sarkar, M.J. Brunger,  J. Phys.: B At. & Mol. Phys. 41 (2008) 085201.

[2] Low energy positron scattering from methanol and ethanol:Total cross sections, Antonio Zecca, Luca Chiari, A. Sarkar, Kate L. Nixon and M.J. Brunger,  Phys. Rev. A  78 (2008) 022703.

[3] Positron scattering from Formic acid, Antonio Zecca, Luca Chiari, A. Sarkar, Marco A.P. Lima, Marcio H.F. Bettega, Kate L. Nixon and M.J. Brunger, Phys. Rev. A  78 (2009) 042707.

[4] Total cross sections for positron scattering H₂ at low energies, Antonio Zecca, Luca Chiari, A. Sarkar, Kate L. Nixon and M.J. Brunger, Phys. Rev. A 80 (2009) 032702.

[5] Procedures for conditioning W and Ni moderators for application in positron scattering measurements, Antonio Zecca, Luca Chiari, A. Sarkar, S. Chattopadhyay and M.J. Brunger, Nucl. Instrum. & Meth. B 268 (2010) 533.

[6] Total cross section measurements for positron scattering from acetone, Antonio Zecca, Luca Chiari, Emanuele Trainotti, A. Sarkar, and M.J. Brunger, PMC Phys. B 3 (2010) 4.

[7] Positron scattering from the isoelectronic molecules N₂, CO and C₂H₂, A. Zecca, L. Chiari, A. Sarkar and M.J. Brunger, New J. Phys. 13 (2012) 115001.

[8] Positron scattering from Ar, A. Zecca, L. Chiari, A. Sarkar and M.J. Brunger, J. Phys.: B At. & Mol. Phys. 45 (2012) 015203.

[9]  Positron scattering from methane, A. Zecca, L. Chiari, E. Trainotti, A. Sarkar, S. d’ A. Sanchez, M. H.F. Bettega, M. T. do N. Varella, M.A.P. Lima and M.J. Brunger, Phys. Rev. A 85 (2012) 012707.

(E) Reports

[1] Electron momentum density redistribution in YBCO across the superconducting transition, C. Sternemann, M. Volmer, R. Fendt, A. Sarkar, M. Tolan, Udayan De, T. Wolf, T. Buslaps and N. Hiraoka, ESRF (Grenoble) user report 2004.

(F) Books

[1] Studies of Cu-based High Temperature Superconductors by Using Coincidence Doppler Broadening of the Electron Positron Annihilation Radiation Measurement Technique, Mahuya Chakrabarti, A. Sarkar, S. Chattopadhyay, D. Sanyal, New Topics in Superconductivity Research (Ed. Barry P. Martins), Nova Science Publishers, New York (2005).

(G) Communicated/In preparation

[1] Donors and acceptors in heat treated granular ZnO, S. Chattopadhyay, A. Sarkar, S. Pal, S. K. Ray and D. Jana, (In preperation).

[2] Positron annihilation lifetime characterization of oxygen ion irradiated rutile ZnO, H. Luitel, A. Sarkar, M. Chakrabarti, S. Chattopadhyay, K. Asokan and D. Sanyal (Communicated to NIM B)

(H) Papers/Abstracts in symposium proceedings

[1] Understanding the direction of T_c in superconductors due to particle irradiation, Udayan De, A. Sarkar, D. Sanyal, Ravi Kumar and D.  Banerjee, Intrernational Workshop on High- T_c Superconductors, Rajshahi, Bangladesh, November 2-6, 1998.

[2] Altered normal state and superconductivity in Li⁺³ - irradiated Bi-HTSC, A. Sarkar, Udayan De, D. Sanyal, Ravi Kumar and D. Banerjee, Seventh National Symposium on Cryogenics, Nagpur, India, February 22-24, 1999.

[3] Defect dependence of fluctuation conductivity in Bi-HTSC, A. Sarkar, Udayan De, D. Sanyal, Ravi Kumar and D. Banerjee, International Conf. on Defects in Correlated Electron System, Dresden, Germany, July 20-25, 2001.

[4] Fluctuation conductivity in differently heat treated Bi-HTSC, A. Sarkar, D. Sanyal, Udayan De and D. Banerjee, International Symposium on Advances in Superconductivity & Magnetism: Materials, Mechanisms & Devices, Mangalore, India, September 25-28, 2001.

[5] Novel findings for differently heat treated CdO, Udayan De, A. Sarkar, A. Sanyal, K.C.Verma, Soma Dey, D. Banerjee and Sikha Verma, 44^th DAE-Solid State Physics Symposium, Mumbai, India, December 26-30, 2001 (published as proceedings in Solid State Physics India, Vol. 44).

[6] Study of 50 MeV Li³⁺ irradiation induced changes in La_0.7Pb_0.3MnO₃, S. Chattopadhyay, A. Banerjee, A. Sarkar, Ravi Kumar, B.K. Chaudhuri and D. Banerjee, 21^st International Conference on Nuclear Tracks in Solids, New Delhi, India, October 21-25, 2002.   

[7] Interesting observations from positron annihilation studies on spinel oxide nanoparticles, S. Chattopadhyay, R.N. Bhowmik and A. Sarkar, International Conference on Nanoscience and Technology, Kolkata, India, December 17-20, 2003.

[8] Resistivity Peculiarities in Cadmium Oxide Material at Low Temperatures, K.C. Verma, A. Das, A. Sarkar and Udayan De, 46^th DAE-Solid State Physics Symposium, Gwalior, India, December 26-30, 2003. (published as proceedings in Solid State Physics India,  Vol. 46). 

[9] Investigations on annealed ZnO sample by positron annihilation spectroscopy, Sreetama Dutta, M. Chakraborti, S. Chattopadhyay, A. Sarkar, D. Sanyal, and D. Jana, Condensed Matter Days-2004, Shilong, India, August 25-28, 2004. 

[10] Defect dynamics in ion irradiated Bi-2212 studied from in-beam resistivity measurements, A. Sarkar, D. Sanyal, Ravi Kumar and Udayan De, Indo-German Workshop on Synthesis and Modification of Nano-structured Materials by Energetic Ion Beams, New Delhi, India, February 20-24, 2005. 

[11] Interesting observations from positron annihilation in nano-sized Zn(Ag)S, A. Banerjee, Sanat Manik, Mahuya Chakraborti, S. Chattopadhyay, S.K. Pradhan, D. Sanyal and A. Sarkar, Int. Conf. on Nanoscience and Technology (ICONSAT 2006), New Delhi, India, March 16-18, 2006.

[12] Defect identification in ZnO by positron spectroscopy, A. Sarkar, Mahuya Chakraborti, Sreetama Dutta, S. Chattopadhyay, D. Sanyal and D. Jana, Int. Conf. on Laser and Nanomaterials (ICLAN 2006), Kolkata, India, Nov. 30- Dec. 02, 2006.

[14] Electrical resistivity peculiarities and positron lifetime in annealed CdO,  A. Sarkar, S. Chattopadhyay and Udayan De, 15^th Int. Conf. on Positron Annihilation (ICPA-15), Kolkata,  India, January 18-23, 2009.  

[15] Nature of normal state resistivity in high temperature superconductors, A. Sarkar, S. Chattopadhyay, R. Rawat and Ravi Kumar, Int. Conf. on Magnetic Materials (ICMM), Kolkata,  India, October 25-29, 2010.

[16] Positron annihilation spectroscopic studies on La_1-xA_xMnO₃ (A= Ca, Sr, Pb and Ba) system, S. Chattopadhyay, A. Sarkar, M. Chakraborti, D. Sanyal, M. Kar, National Workshop on Application of Radiation in Physical, Chemical and Life Sciences, Kolkata, India, September 4-6, 2013. (Proceedings in press)

                                                            Invited talk(s)

[1] Conference on Positron/Positronium Annihilation, 2^nd Feb. 2004, Saha Institute of Nuclear Physics, Kolkata, India.

[2] Discussion Meeting on Materials science using Low energy ion beams, 9^th Sept. 2012, Inter University Accelerator Centre, New Delhi, India.

[3] DAE-BRNS theme meeting on Positron Annihilation Spectroscopy, 9-10   December, 2013, Bhaba Atomic Research Centre, Mumbai, India.

[4] Oral presentation entitled “Point defects in 6 MeV H⁺ ion irradiated ZnO single crystal”, A. Sarkar, M. Chakrabarti, T. Rakhsit, S. K. Ray and D. Sanyal, in “Condensed Matter Days 2014” Kolkata, India, August 27-29, 2014.

[5] Oral presentation entitled “Defects in 6 MeV H⁺ ion irradiated ZnO single crystal: theory and experiment” A. Sarkar, M. Chakrabarti, T. Rakhsit, S. K. Ray, D. Rafaja and D. Sanyal, in Int. Conf. on “Swift Heavy Ions in Materials Engineering and Characerization (SHIMEC 2014)”, New Delhi, India, October 14-17, 2014.    

Workshops/Schools/Seminars attended (Without abstract)

[1] School on Accelarator Based Science & Technology at Nuclear Science Centre (NSC), New Delhi, India, April 14-24, 1998.

[2] Workshop on Swift Heavy Ions in Materials; Basic Phenomena & Applications at Nuclear Science Centre (NSC), New Delhi, India, October 24^th, 1998.

[3] International School on Powder Diffraction at Indian Association for the Cultivation of Science (IACS), Kolkata, India, 7-10 October, 1998.

[4] Workshop on Experiments at Low Temperature at Inter-University Consortium, Indore, India, 1-12 December, 1999.

[5] Workshop on Radioactive Ion Beams at Puri, India, 24^th October, 2000.

Research Projects:

Ongoing and completed projects

[1] Successfully completed a minor research project entitled “Defect identification and their correlation with optical properties of II-VI semiconductors” funded by University Grants Commission, Govt. of India (Sanction number: PSW-029/05-06, Tenure: 02.05.2006-01.05.2008).

[2] Co-investigator of a minor research project entitled “Defect induced magnetic properties of manganites” funded by University Grants Commission, Govt. of India (Sanction number: PSW-130/10-11, Tenure: 20.10.10-19.10.12).

Collaborations:

Collaborative work with other laboratories

[1] With Variable Energy Cyclotron Centre (VECC), Kolkata.

[2] With Nuclear Science Centre (NSC), New Delhi.

[3] With University of Burdwan (BU), Burdwan.

[4] With Indian Institute of Technology (IIT), Kharagpur

[5] With Inter University Consortium (IUC), Kolkata.

Special Achievements:

International Exposure

[1] Visited ESRF, Grenoble, to carry out experiment on Compton scattering in HTSC materials during phase transition.

[2] Visited Grenoble High Magnetic Field Laboratory.

[3] Visited Positron Collision Laboratory (2007 & 2009), Dipartimento di Fisika, Universita di Trento, to carry out experiments on positron scattering with molecular gases.