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Highlight Lecture

WEB Challenges in controlling dielectric permittivity in precursor derived ceramics

Thursday (24.09.2020)
11:35 - 11:50 Z: Special Symposia I
Part of:


Materials with colossal dielectric permittivity [CP, (ε'>10^3)] have attracted attention in recent times for the

 

realization of modern electronic devices with high energy storage density. To increase the performance index of CP

 

materials, it is desirable to possess stability at high temperatures and frequencies coupled with low dielectric loss.

 

Obtaining colossal permittivity concomitant with minimal dielectric loss is always a challenge and therefore is an

 

important avenue for advancement of energy storage technology. Recently, dielectric behavior of polymer-derived

 

amorphous silicon carbonitrides (SiCN) have been reported . These materials have demonstrated colossal

 

dielectric constant (ε'>103) with low dielectric loss (tanδ <10), which retains even at higher temperatures. This

 

enormous dielectric permittivity is attributed to an interfacial-charge polarization process occurring at the interphase

 

of ceramic matrix/free-carbon of the material. The study has paved the way for the development of ceramic

 

composites having series of insulating/conducting phases in an amorphous matrix resulting in colossal dielectric

 

values. The current status and potential of PDCs vis-à-vis traditional dielectric materials has been very encouraging

 

. Despite the inherent tremendous potential of PDCs, they are at a nascent stage of development. So far,

 

only the dielectric behavior of SiCN derived from polymer derived ceramics (PDC) have been studied at low

 

frequencies (<10 MHz), multitude of other materials such as SiOC, Si(M)OC, Si(M)CN, SiBCN and Si(M)BCN

 

have not been investigated yet, presenting a wide array of potential PDC derived materials for dielectric applications.

 

Such materials are highly suitable for the development of microelectronics such as transistors, switches for

 

memories and offers the advantage of drastic reduction in size along with weight of the devices. This talk presents

 

some results on the colossal dielectric response observed in PDCs with prototypical examples and material design

 

challenges.

Speaker:
Prof. Dr. Ravi Kumar Nelamane Vijayakumar
Indian Institute of Technology Madras