Influence of proton radiation on the nonlinear current-voltage characteristics of pulsed laser deposited ilmenite-hematite thin films

Abstract

Ilmenite-hematite (IH) [(1-x)FeTiO 3 ·xFe 2 O 3 ] solid solutions are unique classes of materials showing both magnetic and semiconducting properties, which make them potential candidates for novel applications in microelectronics and spintronics. This paper focuses on their varistor behavior before and after exposure to 40 MeV and 10 MeV proton radiations up to a fluence of 5 ϫ 10 10 p/cm 2 . The IH films are tolerant to these irradiations with little significant change to the nonlinear current-voltage characteristics. The switching voltage of the devices is in the regime of practical applications, and the radiation tolerance makes these materials suitable for aerospace applications.Radiation-induced damage has become an important field of study and continues to gain importance because of the need to protect electronic components, devices, and microelectronic circuits from the potentially catastrophic effects of radiation on their performance. 1 Space systems often require electronics that can operate in a high-radiation environment. This radiation may result from particles trapped in planetary magnetic fields, galactic cosmic rays, or high-energy protons from solar events. Exposure to high energetic particles can degrade device performance and ultimately lead to component failure. The primary effects of natural space radiation on spacecraft electronics are total ionizing dose effects, displacement damage, and single event upsets. 2 Radiation can alter the characteristics of electronic materials and the performance of electronic devices made from these materials by the mechanisms of ionization and atomic displacement. The displacement damage takes place by nuclear interactions and the ionization damage by atomic interactions in which energy deposited by the ionizing radiations creates electron-hole pairs. Semiconductor-based sensors, such as varistors and other current sensitive sensors, have applications in aerospace and other hostile environments for power and other applications. The radiation effects on device performance are important in these applications because the elevated radiation levels associated with these environments can produce both ionization and displacement damage.

Novel magnetic-semiconductors in modified iron titanates for radhard electronics

“…However, when two-point measurements were conducted on the same sample highly non-linear I-V relationship was observed, consistent to our previous observations reported in [4,7,13,15,17,18]. A careful analysis suggested the existence of Schottky barriers which is the basis of all metal-semiconductor devices.…”

“…Bulk ceramic samples were prepared using the standard technique of ball milling the raw materials, pressing at high pressure using a uniaxial press followed by sintering and finally annealing the green ceramic at high temperatures. The details are given in many of our papers referenced here but the reference number [5,13,15] will be of special interest to those interested in processing dense, homogeneous ceramic samples of IH. We have studied also the textured and epitaxial films of different compositions of IH, primary among them being those with x=0.33 and x= 0.45.…”

“…Our varistor devices based on IH ceramic switch at low voltages (<5 V) and they have excellent immunity to radiation [13,15]. Low voltage switching makes them attractive for integration with microelectronics and radiation immunity for radhard electronics.…”

“…Of special interests are IHF33 and IHC45, and single crystals of pseudobrookite (PsB). Some of these studies have been reported in references [6,7,[12][13][14][15][16][17][18][19]. In this paper our emphasis will be on materials characterization for radhard electronics, evaluation of magnetically and electrically tuned varistors and effect of a biasing voltage on the non-linear current-voltage (I-V) characteristics.…”

Magnetically tuned varistor-transistor hybrid device

“…6 Both IHC33 and IHC45 are also excellent radhard materials. 6,[8][9][10][11] Therefore, the devices described here are expected to perform satisfactorily even when exposed to radiations such as in space. The non-linear I-V characteristics for a wide range of compositions for ceramic samples of IH with 0 < x < 0.45 is reported in reference .…”