Work In Progress!

Posts in category Masters Research

The refrigerator next door

dilution refrigerator open

The neighbours have a refrigerator that’s guarded 24×7 by a grad student in spite of the fact that there never is any ice cream in it. It can cool its contents to around 10mK , subject to heat load . Designed by Oxford Instruments, this dilution refrigerator uses a mixture of He-4 and its isotope […]

MFP-3D Atomic Force Microscope

Magnetic Domains were created on a  BFO sample using lithography, and imaged using the MFM mode.

An Introduction to the MFP-3D AFM installed at the SpinLab, IISER Mohali. I have Co-Authored a paper on the surface topography of moth wings imaged with this AFM, which includes a discussion on the relevance of the discovered patterns in the flight of winged insects. It appeared in Applied Physics Letters and the the […]

PCAR Spectroscopy

A niobium tip facing a gold film. 0.1mm gold wire contacts on the film were made with silver epoxy.

Contacts between conductors can be classified based on their radius , and the smallest radius possible for a conducting pathway is limited by the de-Broglie wavelength of the electron (Topinka 2000). Electrons flowing through conductors wider than the mean free path routinely undergo scattering by phonons and other elementary excitations, but the current-voltage characteristics of […]

Liquid Helium Cryostat

The radiation bafffles are visible on the dynamic VTI being lowered into the cryostat

A pictorial walkthrough of the installation of the He-4 based Cryostat at the SpinLab, IISER Mohali.  This cryostat is equipped with a 3-axis vector magnet and a dynamic VTI capable of cooling samples down to 2 Kelvin. Special care has been taken to isolate this American Magnetics designed cryostat from ground as well as acoustic […]

Masters Thesis Full Text


The Following is the introductory section from my Masters thesis work during the academic session 2013-14 Full Text of my dissertation submitted to IISER Mohali towards completion of BS-MS dual degree. Download

Na2IrO3 deposition+Imaging

PLD of sodium Irridate

A documented wild goose chase of attempting to produce thin films of sodium irridate using Pulsed Laser Deposition and characterizing surface topography with the Atomic Force Microscope. Towards the end of this process, a scanning electron microscope with EDS was installed.  The EDS data revealed that the thin films produced were actually IrO3.

Probes for Cryostats

Planar copper coils were wound using a hand drill and used to develop an AC susceptometry setup.
A potentially superconducting sample is sandwiched between these, and the mutual inductance is monitored as a function of temperature

  At the SpinLab I had access to a 2″ cryostat capable of cooling down to sub 2K, and it was equipped with a 3-axis vector magnet. With the help of local machinists, I developed a few odd probes compatible with this cryostat as well as with a 1″ PPMS cryostat belonging to a neighbor. […]

Scanning Tunneling Microscopy


Part of my thesis work involved developing a room temperature prototype of a scanning tunneling microscope(STM). Please refer to the full text of my thesis for a more elaborate write-up. The STM was used to study the structure of Highly ordered pyrolytic graphite(HOPG) at room temperature, and monolayer steps were imaged. The thickness of each […]

Thin Film Deposition


An introduction to some of the thin film deposition equipment and materials I have worked with! Overview of the vacuum chamber at the Spin-lab, IISER Mohali. During my time at the Spin-Lab at IISER Mohali, one multi-purpose vacuum chamber designed by Excel Instruments was dedicated for thin film deposition. The system was custom built in […]