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Dr. RAMUDU MACHAVARAPU

ABOUT
NAME: Dr. RAMUDU MACHAVARAPU

MS: M. Sc (Physics)-Sri Venkateswara University

E- MAIL: macrams2@gmail.com

POSITION: Adhoc Faculty

PhD: University of Hyderabad

PHONE: +91 9949142717


AREAS OF INTEREST: Spintronic Materials, Thermal / Ferromagnetic shape memory alloys and thin films, Magnetic Sensors, Magnetocaloric Materials, Rare-earth and rare-earth free based permanent magnetic materials.

BRIEF

Courses Taught

UG:

1. Engineering Physics (PH101)

2. Enginnering Physics Laboratory (PH102)

3. Electronic and Magnetic Materials ( II Year II Sem) (PH285)

Professional (Work) Experience

  • Ad-hoc faculty in the School of Sciences (Physics), National Institute of Technology Andhra Pradesh (NIT-AP), Tadepalligudem, West Godavari-534101, Andhra Pradesh, India from August 12th 2016 to till date. 
  • Research Associate (RA) at Advanced Magnetics Group (AMG), Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh, Hyderabad – 500058, India from August 12th, 2014 to August 11th 2016.
  •   Research Assistance in School of Physics, University of Hyderabad, Hyderabad from July 2nd 2014 to Aug 11th 2014.
  • Postdoctoral Researcher in Johannes Gutenberg University of Mainz, Mainz, Germany, from August 14th 2012 to August 31st 2013. Worked on ferromagnetic shape memory alloy thin films of Ni-Co-Mn-Sn system.

Educational Qualifications:

  • Doctor of Philosophy (Ph.D.) in Physics, University of Hyderabad Degree awarded (June 2012)           

                       Specialization           :  Condensed Matter Physics (Magnetism)

                      Title of the thesis      : Investigations on Ni53.5Mn26.0Ga20.5 shape memory alloy and the effect of boron addition on its properties

  •   Master of Science (M.Sc.) from Sri Venkateswara University in Physics Stream, 2004 FIRST CLASS with DISTINCTION           
  •   Bachelor of Science (B.Sc.) (MPCs) from Sri Venkateswara University, Tirupati, 2002 FIRST CLASS with DISTINCTION
  •   Intermediate/10+2 from Board of Intermediate Education, Andhra Pradesh, 1999 FIRST CLASS
  •   Class X (SSC) from Board of Secondary Education, Andhra Pradesh, 1997 with FIRST CLASS

Research Interests

  • Development of materials for various applications like magnetic refrigeration, magnetic sensors and magnetic tunnel junctions for spintronic devices
  • Spintronic, Thermal / Ferromagnetic shape memory alloys and thin films
  • Rare-earth and rare-earth free based permanent magnetic materials
  • Thin / Thick films of magnetic materials

Hands on experience

  •   Thin film deposition using Ultra High Vacuum (UHV) dc magnetron sputtering system.
  •   Magneto optic kerr effect (MOKE) microscopy.
  •   B-H loop tracer for recording demagnetization curves.
  •   Photolithography for making nano structures and free-standing bridges on thin films.
  •   Induction melting and Vacuum arc melting furnace for making alloys.
  •   High temperature Vibrating Sample Magnetometer (HTVSM) (LakeShore make).
  •   Superconducting quantum interference device (SQUID) magnetometer for magnetic measurements.
  •   Physical Property Measurement System PPMS (Quantum Design-make) with various attachments like Vibrating Sample Magnetometer (with Oven), ac susceptibility measurement,     Resistivity, thermal transport measurement etc.

                 Microscopes like

  • Metallurgical Optical Microscope with Polarizer attachment (Zeiss make, Axiovert)
  • Scanning Electron Microscope (FEI-make, XL30 ESEM)
  • Field Emission Scanning Electron Microscope FE-SEM (Zeiss make, Ultra 55)
  • Low Speed Diamond Saw, ISOMET 1000 and an Auto-polisher of Buehler make. Developed expertise in preparing samples for observation under SEM and TEM.
  • Programmable instruments like dc constant current source , ac/dc current source , nano-voltmeter, cryogenic temperature controller , lock-in amplifier (Stanford-make, model SR830), multimeters etc.
  • Furnaces operating to 1200oC / 1500oC controlled by programmable temperature controller and thyristor (Eurotherm-make/ WEST-make).

Work experience in projects

  •   Worked as a Junior Research Fellow (JRF) in UGC-CAS under “Research Fellowships in Sciences for Meritorious Students (RFSMS)” program during November 2007 – June 2010.
  •   Worked as a Senior Research Fellow (SRF) an applied project entitled “Development of Ferromagnetic Shape Memory Alloys materials based Actuators”, sponsored by ADA (Aeronautical Development Agency) during the period September 2006 – November 2007.
  • Worked as a Project Assistant in a project “Development of Ferromagnetic Shape Memory Alloys materials based Actuators”, sponsored by ADA (Aeronautical Development Agency) during the period January 2006 – September 2006.

Books Published

Title: Effect of boron addition on the properties of Ni53.5Mn26.0Ga20.5 alloy: Effect of boron addition on the crystal structure, microstructural, magnetic and mechanical properties

Publisher: LAP LAMBERT Academic Publishing (2012-10-08) ISBN: 978-3-659-25701-8

List of Publications

1. Structure, magnetic properties and electrical resistivity of Co2FeSi1-xGax Heusler Alloy thin films, M. Ramudu, M. Manivel Raja, J. Arout Chelvane and S. V. Kamat, J. Magn. Magn. Mater. 418 (2016) 42-47.

2. Half-metallicity in Heusler type Fe2Cr1-xCoxSi alloys, M. Ramudu, Swaleha Inamdar, J. Arout Chelvane, M. Manivel Raja and S.V. Kamat, J. Phys. D: Appl. Phys. 49 (2016) 055001 (8 pp)

3. Effect of process temperature on structure, microstructure, residual stresses and soft magnetic properties of sputtered Fe70Co30 thin films,     Swaleha Inamdar, M. Ramudu, M. Manivel Raja and S.V. Kamat, J. Magn. Magn. Mater. 418 (2016) 175-180.

 4. Role of processing parameters on the morphology and magnetic properties of Tb–Fe–Co thin films, K. Uma Devi, J. Arout Chelvane, Himalay Basumatary, M. Ramudu, S. V. Kamat and V. Jayalakshmi, J. Magn. Magn. Mater. 418 (2016) 163-168.

 5. Investigations on Ni-Co-Mn-Sn thin films: Effect of substrate temperature and Ar gas pressure on the martensitic transformations and exchange       bias properties, Ramudu Machavarapu and Gerhard Jakob, AIP Advances 5 (2015) 037108.

 6. Exchange bias effect in the martensitic state of Ni-Co-Mn-Sn film, RamuduMachavarapu and Gerhard Jakob, Appl. Phys. Lett. 102 (2013) 232406.

 7. Influence of boron addition on the microstructure, structural and magnetic properties of Ni53.5Mn26.0Ga20.5 alloy, M. Ramudu, A. Satish Kumar and V. Seshubai, Intermetallics 28 (2012) 51-57.

 8. Site preference of magnetic atoms in Ni–Mn–Ga–M (M = Co, Fe) ferromagnetic shape memory alloys, A. Satish Kumar, M. Ramudu and V. Seshubai, Phys. Status Solidi (b) 249 (2012) 620-626.

 9. Structural and magnetic investigations in the vicinity of first order transformations in Ni-Mn-Ga-Co ferromagnetic shape memory alloys, A. Satish Kumar, M. Ramudu and V. Seshubai, Phase Transitions  85(2012) 1045-1059.

10. Effect of selective substitution of Co for Ni or Mn on the superstructure and microstructural properties of Ni50Mn29Ga21, A. Satish Kumar, M. Ramudu and V. Seshubai, J. Alloys Compd. 509 (2011) 8215-8222.

11. Modulated monoclinic crystal structure and large shape memory effect in nickel-rich Ni53.5Mn26.0Ga20.5, M. Ramudu, A. Satish Kumar, V. Seshubai, K. Muraleedharan, K.S. Prasad and T. Rajasekharan, Scripta Mater. 63 (2010) 1073-1076.

International Conference Proceedings:

1. Role of Aging Time on the Magnetic Properties of Sm2Co17 Permanent Magnets Processed Through Cold Isostatic Pressing, M. Ramudu and D. M. Rajkumar, AIP Conf. Proc. 1942 (2018) 130050 (1-3).

2.   Coercivity enhancement in sintered Nd-Fe-B magnets by Dy diffusion using simple vapor deposition technique, M. Ramudu, N. V. Rama Rao and S. Pandian, AIP Conf. Proc. 1832 (2017) 130057 (1-3).

3. Effect of Boron on the Structural And Magnetic Properties of Co2FeSi1-xBx Heusler Alloys, M. Ramudu, M. Manivel Raja and S. V. Kamat, AIP Conf. Proc. 1731 (2016) 130017(1-3)

4. Correlation of martensitic transformation temperatures of Ni-Mn-Ga/Al-X alloys to non-bonding electron concentration, M. Ramudu, A. Satish Kumar, V. Seshubai and T. Rajasekharan, IOP Conf. Series: Materials Science and Engineering 73 (2015) 012074.

 5. Influence of boron on the microstructural and mechanical properties of Ni53.5Mn26.0Ga20.5 shape memory alloy, M. Ramudu, A. Satish Kumar, V. Seshubai and T. Rajasekharan, AIP Conf. Proc. 1591 (2014) 1598-1600.

6. Influence of site occupancy on the structure, microstructure and magnetic properties of ternary and quasi-ternary alloys of Ni-Mn-Ga, V. Seshubai, A. Satish Kumar and M. Ramudu, AIP Conf. Proc. 1461 (2012) 74-86.

Conferences attended

  1. Poster presented in DAE-SSPS-2017 at BARC Mumbai during 26-30 December 2017. 
  2. Poster presented in International Conference on Magnetic Materials and Applications ICMAGMA-2017 at Hyderabad during 1-3 February, 2017.
  3. Poster presented in DAE-SSPS-2016 at KITT-Bhubaneswar during 26-30 December, 2016.
  4. Poster presented in DAE-SSPS-2015 at AMITY University, New Delhi during 21-25 December 2015. 
  5. Oral Presentation and Poster presentations in International Conference on Magnetic Materials and Applications ICMAGMA-2015 at VIT-Vellore during 2-4 December, 2015.
  6.  Poster presentation in International Conference on Magnetic Materials and Applications (ICMAGMA) – 2014, Pondicherry University, Puducherry, India during 17th – 19th September 2014
  7. Poster presented in DAE-SSPS-2013 at THAPAR University, PATIALA, PUNJAB during 17-21 December 2013
  8. Poster presentation in  DPG Conference 2013 at Regensburg, Germany during 11-15th March 2013
  9. Oral presentation inInternational Conference on Materials Science and Technology (ICMST)-2012 at Kerala during 10-14 June 2012
  10. Poster presentation in National Conference on Magnetic Materials and Applications (MagMA-2012) during March 12-13, 2012 at IITM, Chennai
  11. Poster presentation in India-Singapore Joint Physics Symposium 2010 (ISJPS-2010) during February 19-21, 2010 at University of Hyderabad, Hyderabad, India
  12. Poster presentation, Proceedings of 54th DAE-Solid State Physics Symposium, during December 14-18, 2009, Vadodara, India
  13. Poster presentation in International Conference on Condensed Matter Physics (ICCMP-2007) during November 25-28, 2007, Jaipur, India.

Workshops Attended

  1. Two day Faculty Development Program on “Effective Teaching and Evaluation Methods in Engineering Education”, organized by Teaching-Learning Centre, NIT Warangal at NIT Andhra Pradesh, Tadepalligudem during April 1-2, 2017.
  2. “Targeted Training Program on Quantitative Electron Microscopy”, organized by Defence Metallurgical Research Laboratory (DMRL), Hyderabad, during December 15-17, 2014.
  3. “Awareness workshop of UGC-DAE consortium for scientific research” organized at School of Physics, University of Hyderabad during October 28-30, 2013.
  4. Workshop on “Physics at small scales” organized at School of Physics, University of Hyderabad during March 18-19, 2011.
  5. India-Singapore Joint Physics Symposium 2010 (ISJPS-2010), organized at University of Hyderabad, Hyderabad during February 19-21, 2010.
  6. “University of Hyderabad – Tata Institute of Fundamental Research (UoH-TIFR) Interaction Meeting organized at University of Hyderabad, Hyderabad during August 20-22, 2009.
  7. “Workshop on Low Temperature Physics” Organized at School of Physics, University of Hyderabad during March 14-15, 2008.
  8. “Workshop practice school on Machine drawing and machining” organized at Science complex workshop, University of Hyderabad during June 17-23, 2008.
  9. International Conference on Ferromagnetic Shape Memory Alloys (ICFSMA-2007) at S.N. Bose National Centre for Basic Sciences, Kolkata during November 14-16, 2007.
  10. “Workshop on Superconductivity” organized at University of Hyderabad during January 27-28, 2007

Papers Reviewed

  • Journal of Magnetism and Magnetic Materials
  • AIP Advances
  • DAE-SSPS-2018
  • DAE-SSPS 2017
  • DAE-SSPS 2016

Memberships

Life Member, Magnetics Society of India (MSI)

AWARDS

  • Stood University Topper in M.Sc. and received Prof. Y. Prabhakar Reddy University Gold medal.
  • Received Prof. P. Jayarami Reddy University Gold medal for securing first rank in Quantum Mechanics subject in M.Sc.

Additional

Attended a summer training program for students in Physical Research Laboratory (PRL) during May – July 2003, Ahmedabad, India and undergone a research project entitled “A study of second order optical vortices”.esearch Interests