Transport and Thermal studies on systems of Novel ground states

The domain of low temperature physics is enriched due to the presence of various phase transitions in a range of materials. The development of materials that exhibit such transitions provide a vide platform to study the underlying the basics. Now¬a¬days, the investigations started revealing that the ground states of such materials are often unconventional. This has evolved because of the availability of sophisticated tools to unravel such phenomena. One such domain is the utilization of low temperatures and high magnetic fields (LTHM). During the past three decades extensive research is being carried out in generating alternative materials for conventional refrigeration and is a consequence of global concern is using liquefied gases as working substance. Magneto caloric and thermoelectric materials show promise in this arena. We have chosen examples from the former one viz RCo2 systems to show certain interesting manifestations of the grounds states. The second part we dealt is with YCo2 system which is a Pauli paramagnet that turns to a ferromagnetic ground state upon disorder with Nd. In this system we could show the divergence of many of the observed parameters around a critical concentration of Nd in Y that resembles the ‘QCP like’ behavior. This also helped us to study the associated NFL type behavior associated with the anomalies. Finally, some recent work will be presented on new Fe based chalcogenides superconductors, where the interplay of magnetic and superconducting properties manifest heavily. Extensive investigations were carried out to show the induction of superconductivity in FeTe based superconductors and the substitution effects in FeSe system. The primary aim is to study how the ground state properties are affected by disorder as well as magnetic fields.