Magnetically Tuned Varistor and Its Embedded Transistors

• Main Authors: Raghvendra K. Pandey, William A. Stapleton, Rainer Schad
• Format: Article
• Language: English
• Published: IEEE 2016-01-01
• Series: IEEE Journal of the Electron Devices Society
• Subjects: Varistors; transistors; HFET; MAGFET; spin transistors
• Online Access: https://ieeexplore.ieee.org/document/7489046/
• ISSN: 2168-6734

This paper describes the properties and potential applications of a hybrid device consisting of a varistor diode and its embedded transistor whose origin lies in a magnetically tuned varistor diode. It is shown how the output current (or voltage) of a varistor based on a magnetic oxide semiconductor can be manipulated by the application of a magnetic field to produce an embedded device with characteristics similar to that of a conventional transistor. Following the tradition of microelectronics, we name it the HFET transistor where H stands for a magnetic field. Two types of embedded HFET devices are described here; one with the current-voltage (I-V) characteristics and the other with voltage-current (V-I) characteristics. Both I-V and V-I devices exhibit high degree of nonlinearly but only in the V-I mode of the HFET device well-developed saturation regions of output signals are found. The room temperature HFET in its V-I mode appears to be also a good electronic switch with well-defined “off” and “on” states. Saturated regions of output signals and electronic switching are the signature property of these HFET transistors along with the capacity of providing a good level of signal amplification. When cooled to 100 K the HFET V-I device appears to lose partially the electronic switching property but gain in signal amplifying potential. The HFET device in I-V mode does not display the defining properties of electronic switching but can amplify signals by almost 400%.