You are cordially invited to UNAM Nanocolloquium seminars focusing on advancements in the field of nanoscience and nanotechnology. The seminars bring us the most recent developments in these exciting fields. This week’s talk will be presented by Prof. Mehdi Fardmanesh*.
Title: Low Noise High-Tc SQUID Fabrication & system development for NDE and MCG applications
Date: March 24, 2023 (Friday)
Time: 16:00
Topic: Nanocolloquium series
UNAM Conference Hall
& This is also an online seminar. To obtain event details please send a message to department.
ABSTRACT:
In this presentation, after a short review of the principal operation and advantages of high temperature superconductive SQUIDs, the development and characteristics of the fabricated devices will be discussed. Low noise high temperature superconductive Josephson junctions for rf-SQUID fabrication have been designed and fabricated using superconductive YBCO thin films. The films were made by a combination of magnetron sputtering and/or MOD techniques on various engineered crystalline substrates such as SrTiO3 and LaAlO3 substrates. Then after a short review on the performance of the fabricated devices, the fabrication of background magnetic field insensitive rf-SQUIDs will be presented. The SQUIDs are step-edge junction type made on substrates patterned by IBE. Incorporating made rf-SQUID magnetic sensors, Non Destructive Evaluation (NDE) and Magneto Cardiography (MCG) systems were developed in the laboratory. A SQUID based non-magnetic robotic 2D NDE system was successfully designed and developed using coil based induction, with a combination of rf-SQUIDs in gradiometric structure as well as excitation coils in differential mode. The designed and implemented magnetocardiograph system consists of two High Tc rf-SQUID magnetometers, which are placed in an axial gradiometer arrangement. The system is based on a designed liquid nitrogen dewar with rf-interference aluminum shield and appropriate structure for short liftoff. The implemented active shield is made of two stages of shielding system while each of them has been designed for different frequency and dynamic range characteristics. Using the developed combinatorial shielding system, the disturbing magnetic signals of the environment could be attenuated successfully. The system incorporates a designed two channel rf SQUID electronic readout.
About the Speaker:
Mehdi Fardmanesh received the B.S. degree in electrical engineering from Amirkabir (Tehran Polytechnic) University, Tehran, Iran, in 1987, and the M.S. and Ph.D. degrees in electrical engineering from Drexel University, Philadelphia, PA, in 1991, and 1993, respectively. Until 1993, he conducted research on development of thin- and thick-film high-temperature superconducting materials, devices, and development of ultralow-noise cryogenic characterization systems at Drexel University, where he also taught electronics circuits. From 1994 to 1996, he was the Principal Manager for research and development and the Director of a private-sector research electrophysics laboratory while also teaching in the EE and Physics departments of Sharif University of Technology, in Tehran. In 1996, he joined the EEE Department of Bilkent University, in Ankara, Turkey, teaching in the areas of solid state and electronics while also supervising his established Superconductivity Research Laboratory at Bilkent. In 1998 and 1999, he was invited to ISI-Forschungszentrum Juelich, Juelich, Germany, where he pursued the development of low-noise high-rf-SQUID magnetic sensors. From 2000 to 2004 in Juelich Research Center, he was the director of a joint international project for the development of high-resolution high-Tc SQUID-based magnetic imaging system (SQUID microscope) for biomedical applications. In 2002, he reestablished his activities with the EE Department of Sharif University, where he is a tenured professor and head of the “Superconductivity & advanced devices research laboratory,” which he established in 2003 and he has directed since then. He has supervised more than 100 graduate students and is the holder of several international patents in the areas mentioned, and teaches courses in the field of Solid state Physics, and Electronic Devices, Nano and Microelectronics materials, Biosensors as well as Electronics and Bio-electronic Circuits nationally and internationally.
*Sharif University of Technology