Phase transitions in electrostatic doping.

In this project a different doping mechanism is employed to study the metal-insulator transitions. Known as electrostatic doping, this mechanism utilizes the FET (Field Effect Transistor) structure to induce charge carriers to the material being studied. Compared to chemical substitution, electrostatic doping is reversible, uniform, flexible and is a convenient way of manipulating carrier density in phase transitions. In this thesis design and fabrication procedure of field effect transistors on SrTiO3 single crystals is described. Important parameters of the fabrication are discussed and optimization of these parameters in order to achieve the desired effects is explained. Moreover, successful FET characteristics are presented. Increase of the channel current by 5 orders of magnitude while gate voltage is swept from 0V to 100V and drain voltage is maintained constant is reported. Two-point resistance measurements are performed and decrease of channel resistance by 4 orders of magnitude in the same gate voltage range is also reported.Bachelor of Science in Physic