SURBHI KRISHNA SINGH

Materials Engineer NATIONAL UNIVERSITY OF SINGAPORE

EDUCATIONAL BACKGROUND

• Master of Science (Materials Science and Engineering) - National University of Singapore(NUS)

August 2013 – December 2014

• Bachelor of Technology (Metallurgical and Materials Science Engineering) National Institute of Technology (NIT), Jamshedpur

Graduated May 2013 with CGPA 9.09/10 (First class honors)

PROFESSIONAL EXPERIENCE

1. Graduate Student Researcher, NUS (Dec 2013 – present)

2. Media Advanced Technology Intern, Seagate Technology (May 2014- August 2014)

3. Trainee Decision Scientist at Mu Sigma (May 2013- Jun 2013)

4. Campus Ambassador at Mu Sigma (Sep 2012 - May 2013)

5. Research Trainee at National Metallurgical Laboratory (May 2012 - Jul 2012)

6. Industrial Trainee at Coal India Limited (May 2011 - Jun 2011)

OBJECTIVE : Field Emission Properties of CF4 treated carbon nanotubes and graphene hybrid films

CENTRAL ISSUE :

• Carbon nanotubes and graphene hybrid films were fabricated using electrophoretic deposition(EPD)

• Surface fluorination was performed by CF4 plasma treatment

• These hybrid films have shown improved turn on field and better reliability in past studies

• Surface roughness and thinner field emitters created due to plasma immersion would further improve the electron emission properties

POSITION HELD : Graduate Student Researcher at Carbon Nanotechnology Group

DURATION OF COMPLETION : 6 MONTHS

PROCEDURE :

1. Solution of graphene and carbon nanotubes prepared, electrophoretically deposited(EPD) on Silicon wafer

2. CF4 plasma treatment done for varying durations (1 min , 2 min etc.) using Reactive Ion Etching (RIE) system

3. Field Emission measurements showed the variation in properties of as deposited and plasma treated samples respectively

4. SEM images taken and XPS analysis done, to analyze the surface variation and chemical variation occurred

RESULTS :

1. Lower turn on voltage for plasma etched samples

2. Presence of sharp edges of CF/F deposited ,as shown in the SEM image below

4. Presence of CF (Teflon) on the film for samples treated more than 2 mins

5. Degradation in emission of samples treated for more than 2 mins

IMPACT POINTS :

3. Improved field emission properties obtained for plasma treated films.

4. Optimization of the plasma treatment time needs to be further investigated

5. Work submitted for publication in Applied Surface Science

OBJECTIVE :Study of Sputter Process Across Target Lifetime

CENTRAL ISSUE :

• Electrical, physical, mechanical and magnetic properties have been observed to vary along the target lifetime during sputtering process of magnetic hard disk drive.

• Objective was to analyze, investigate and conclude the trend of different properties vs. target lifetime.

• On the basis of analysis, changes in the existing system would be made

POSITION HELD : Media Advanced Technology Intern at Seagate Technology International, Singapore

DURATION OF COMPLETION : 3 MONTHS

PROCEDURE :

1. Analysis of-• Electrical: VTS parameters (the major 7 parameters)• Physical: Deposition rate, Layer thickness across 3 radius• Magnetic: Hc & Hn & Mrt across 3 radius• Thermal stability: KuV/kT, cHa• Mechanical: Hysitron, CL50, TMIC• Sputter process: Bias current (across target lifetime and halo lifetime), HVPS

2. Analysing trends to see interrelations between properties

3. Drawing the process map based on trends obtained 4. Implementing changes in the system accordingly

RESULTS :1. Variation of Magnetic Properties with change in i) Target Lifetime ii) Power Setting2. Inter relation of VTS and VRDM properties detected3. Power setting and target lifetime relationshiop detected 3. Carbon trends with change in i) target life ii) duration

IMPACT POINTS :

1. Automated system for process setting change with target life in process of implementation at Seagate

2. Regression equations obtained in the analysis are being used to set process KPIVs

OBJECTIVE :High temperature oxidation behavior of superhard nanocomposite Ti-Si-B-C coated stainless steel CENTRAL ISSUE :

• Hard coatings are used in many applications, for example, cutting and polishing tools, molds, dies, hard disk and other wear-resistant applications

• However, for high temperature engineering applications, coating stability is compromised

• Blending together hardness, low friction coefficient, toughness, thermal stability in a coating is a challenge faced by today's scientific and technological community

• Ti-Si-B-C nanocomposite coatings were deposited on Stainless Steel substrate by magnetron sputtering using Ti-Si-B-C target for developing super hard nanocomposite coatings for high temperature applications

POSITION HELD : Research Trainee at National Metallurgical Laboratory(NML)

DURATION OF COMPLETION : 4 MONTHS

PROCEDURE :

1. Magnetron Sputtering deposition of Ti-Si-B-C on stainless steel sample

2. Thermogravimetric Analysis (Cahn Thermax 700 Thermo-gravimetric Analyzer, temperature range 700 °C - 1100°C) to see the high temperature oxidation behavior and obtain oxidized samples for analysis

3. Characterization of film, namely : XRD, AFM, SEM, EDS to see variation in

4. Surface profile measurements, film thickness measurements

5. Nanoindentation test to see modulus , hardness

RESULTS :

6. Modulus of upto 235.284 GPa and Hardness of upto 4.676 GPa obtained for samples oxidized at 1100˚C

7. Good high temperature stability of films

IMPACT POINTS :

The nanocomposite can be put to use in industry for high temperature metalworking applications