Cryogenic magnetic field sensor based on the magnetoresistive effect in bulk Bi2212+USr2CaO6

Abstract

A large magnetoresistive (MR) effect was observed in melt-textured (MT) Bi2212 in which USr2CaO6 was added in a proportion of 6wt%. The resistivity measurements of MT Bi2212+6wt% USr2CaO6 show high sensitivity to applied dc fields, as compared to pure Bi2212, in particular at low fields, below 3T, and in a temperature range between 45K and 85K. In this temperature range, the MR effect of MT Bi2212+6wt% USr2CaO6 is two orders of magnitude larger than the MR effect in pure Bi2212, and display a maximum that may be tuned to a particular temperature within the above range, by changing the amount of added nonsuperconducting compound. A cryogenic sensor was built and tested at 77K in low fields. It shows a good sensitivity and small (∼1%) hysteresis of resistivity when the applied field was cycled between 0T and 1T.

Magnetoresistive effects in Bi-2212 melt textured bulk with MgO additions

“…The resistivity of MT Bi-2212 + 20 wt% MgO displays a high sensitivity to applied magnetic fields when compared with pure Bi-2212 and is comparable to the previously reported Bi-2212 + USr 2 CaO 6 [3,4]. The MR effect is significant below 3 T over a temperature range of 10-90 K without any hysteretic behaviour with cycled applied dc fields.…”

“…These boosted MR levels can be used effectively in the design and preparation of a superconducting magnetic field sensor, making it a practical alternative, at low temperatures, to the commonly used semiconductor sensors. This discovery has led to the recent reporting of a prototype magnetic field sensor based on the MR effect of bulk Bi-2212+USr 2 CaO 6 [3]. In the previous work, USr 2 CaO 6 was found to be compatible with Bi-2212, and the resulting composite was used to make a sensor that was sensitive up to 3 T over an operating range of 45-85 K. It showed no hysteretic effects with thermal cycling.…”

“…Following further investigations of other materials, an alternative to USr 2 CaO 6 has been found and the results are reported in this paper. 3 Author to whom any correspondence should be addressed.…”

Study of dependence upon the magnetic field and transport current of the magnetoresistive effect in YBCO-based bulk composites

“…For this reason, HTSC-based composites with the large MR effect are attractive in terms of their potential practical application in magnetic field sensor devices [1]. Later, the large MR effect was found in the bulk Bi2212 + USr 2 CaO 6 [4,5] and Bi2212 + MgO composites [6]. Also, the sufficiently large MR effect was detected in granular YBCO thick films [7] and BSCCO films [8].…”