NANOscientific

NS: Can you briefly describe your nanoscience and nanotechnology journey and what first ignited your interest in this field?

Ramadurai:

I began my Ph.D. research at the Indian Institute of Science, Bangalore, focusing on the growth of multifunctional oxide superlattice structures and studying their interfacial influences. My work encompassed exploring interfacial coupling in various superlattices and examining strain impact on ferroelectric domains using piezo-force microscopy. Fascinated by nanotechnology, I employed AFM to image nanostructure nucleation sites and utilized PFM and EFM imaging modes. During my postdoctoral fellowship at CRISMAT, ENSICAEN, France, I expanded my focus to fabricating epitaxial nanostructures and employed piezoresonance force microscopy for imaging.

Later, as an Alexander Von Humboldt fellow at Leibniz University of Hannover for two years, I contributed to a project on developing resonant tunnel diode structures with high-k dielectric tunnel barriers. I then pivoted to studying smart materials from multifunctional oxides and nanostructures. Now, at IIT Hyderabad, our lab is centered on researching smart materials and nanoscale devices, focusing on in-situ piezoresponse force imaging of nanostructures.

NS: How has AFM technology, a key focus of your research, evolved over time and what developments are you currently exploring?

Ramadurai:

AFM's evolution from a morphology imaging system to featuring various functional imaging modes has always intrigued me. Our lab at the Indian Institute of Science, Bangalore, housed the first AFM, allowing me to study the nucleation sites of thin films at early growth stages, a challenge I had faced earlier. The introduction of integrated imaging modes like magnetic force and piezoresponse force imaging has made functional domain imaging at the nanoscale possible. Currently, our group is focused on exploring advanced features like imaging surface potentials and mapping force-displacement curves at hybrid material interfaces.

NS: Can you share the areas of nanoscale characterization your research group is focusing on?

Ramadurai:

The research group is now concentrating on imaging functional domains under live conditions, utilizing scanning probe microscopy with in-situ sample stages for imaging amidst various fields and stresses. The primary focus is on the electric and magnetic order of nanomaterials under multiple thermodynamic parameters and analyzing functionalities at the interfaces of hybrid nanocomposites for energy harvesting.

NS: Your research has resulted in numerous publications. Could you discuss some of your most significant findings or contributions to the field?

Ramadurai:

In the early 2006-2008 period, strain engineering was pivotal in studying multiferroics, especially BiFeO₃ (BFO), a prominent room-temperature multiferroic. Our focus was on strain-induced polarization constraints in BFO-based epitaxial superlattices. Using strain engineering and piezoresponse force microscopy, we demonstrated the suppression of specific polarization variants and associated structural transformation in BFO (Ranjith.R et al, APL 96(2010)).

We used strain engineering in BFO epilayers to induce multiphases akin to a morphotropic phase boundary, previously attainable only through compositional variation. This method enhanced the piezoelectric behavior of mixed-phase epilayers, showing a 200% improvement compared to single-phase epilayers (Sajmohan MM et al, JAP 125 (2019)).

Using a piezoresponse force microscope and a specialized X-ray analysis method, we identified the size of strain gradients in nanocomposites, enabling us to attain desired properties in a magnetoelectric composite (Anantha P Bhat et al, ACS Appl. Nano. Mater (2022)).

NS: Can you outline the challenges and opportunities in nanotechnology today, particularly in India?

Ramadurai:

Nanotechnology in India is ripe with opportunities, thanks to supportive government policies and the India Semiconductor Mission. These not only bolster the traditional electronic industry but also encourage innovations in non-conventional fields like sensors and piezoelectrics that don’t demand extensive infrastructure. Startups focusing on nano-devices in sectors like environmental, clean water, and healthcare are pivotal for economic growth. Young researchers are urged to address local challenges through nanotechnology, promising a bright future for the country.

NS: What advice would you give to aspiring nanoscientists and researchers starting their careers?

Ramadurai:

I've discussed nanotechnology's scope in India, but it's a fascinating field globally, with diverse opportunities for interdisciplinary experts. Anyone, regardless of their undergraduate training or degree, can find a nanotechnology aspect aligning with their interests. STEM education is not only engaging but also crucial as the world faces sustainable development challenges requiring specialized knowledge in different nanotechnology areas. So, honing a specific skill set is imperative.

NS: Beyond research and teaching, what hobbies or interests keep you balanced and motivated?

Ramadurai:

Though teaching and research never bore me, two of my major interests outside of these are music, primarily classical Indian flute, and playing soccer. In fact, I hold the record for being the first goal scorer in our institute faculty soccer team during the inter-IIT tournament, a record I believe no one can alter in the history of IIT Hyderabad.

NS: Can you share any exciting upcoming projects or collaborations with our readers?

Ramadurai:

Currently, we are working on a theoretical and experimental combination of mechanically induced electric polarization rotation and the functional domains in and around defective regions of epilayers. We hope that this research will provide significant insights into the material. It involves a combination of theory and experiments, focusing on stress-induced polarization rotation, utilizing a sample stage specifically designed for AFM studies.

NS: What message do you have for the scientific community, particularly young aspirants in nanoscience and technology?

Ramadurai:

To the younger generation, and to some extent, the older generation, I would like to say that science and technology have evolved to a stage where a rigid thought process constrained by disciplinary boundaries no longer holds relevance. We are at a stage where we need to think beyond and across disciplines to work towards a sustainable global future. To be more specific, for the younger generation, I would like to say: be open and stay passionate.