Abstract

Crystals have always attracted humankind from ancient times for their precious properties. Nature has given us many important crystals which has significant, but fixed, properties. Therefore, we need to grow crystals of new synthesized materials of enhanced properties in laboratory under controlled conditions for specific applications.

In the present talk, basic concept of crystals, few crystal growth techniques (like Solution growth, High Temperature Flux growth, Czochralski method, etc.) and some characterization techniques like XRD will be discussed. Then an important class of functional material will be introduced which possesses interesting properties like ferroelectricity, pyroelectricity, piezoelectricity, ferromagnetism, etc. These properties are sensitive to a change in the environment such as temperature, pressure, electric field, magnetic field, etc. and, therefore can be used in transducer, sensor and actuator applications.

Then our recent results in respect of high performance piezoelectric (i) perovskite ABO₃ system (ii) organic crystals (iii) ZnO nanocrystals will be shared. It will be discussed how these grown crystals can be used for energy harvesting applications. Our recent works on the fabrication of patch antenna for GHz communication application will also be discussed.

Key words: Single Crystals, Crystal Growth Techniques, XRD, Piezoelectricity, Energy harvesting, Patch Antenna

Short CV

Dr. Binay Kumar is Professor in the Department of Physics and Astrophysics of Delhi University. During past 28 years of teaching and research, he has taught and mentored thousands of postgraduate students and shaped their career.

He established ‘Crystal Lab’ in the Department of Physics and worked on many technologically important crystals, nanostructures and devices. He was amongst the first to grow high Tc superconducting Bi-2212 crystals, piezoelectric lead based PZNPT/ PMNPT and lead free BNKT/NKLN crystals in our country. In addition, he has grown large variety of optical/NLO organic crystals. Recently he developed a modified Czochralski set-up to grow organic crystals. He has used these crystals to demonstrate many piezoelectric, optical and communication devices.

He has published over 160 research papers in international journals with h-index 32 and i10-index 90, guided 18 students for PhD degree and adjudicated over 50 PhD thesis of other Universities. He has given more than 60 talks in various National and International conferences in USA, Singapore, Spain, etc. He has completed 7 major research projects and happens to be expert / chairperson of funding committee of DRDO and DST. He served as reviewer of many international journals published by Nature, Elsevier, RSC, IOP.

He has been entrusted with many academic responsibilities including external expert of SAP program and Coordinator NAAC expert team to rank other institutions.