Journal of Magnetism and Magnetic Materials,ISSN 0304-8853 Volume 321,Issue 18, 1 Sep 2009, Pages 2733-2736

Observation of large magnetic resistance in weak magnetic fields using CuPt/SiO2/Si/SiO2/CuPt structure

حسن حاج قاسم صابون پز*1 , عليرضا عرفانيان2 , سيده مريم بني هاشميان3 , مجيدرضا علي احمدي , منصور محتشمي فر

1- دانشگاه شهيد بهشتي دانشکده مهندسي برق و کامپيوتر 2- دانشگاه خواجه نصيرالدين طوسي دانشکده مهندسي برق 3-دانشگاه آزاد اسلامي واحد قم

Abstract: The magnetoresistive effect of CuPt(8 nm)/SiO2(5 nm)/Si(50,000 nm)/SiO2(5 nm)/CuPt(8 nm) structure made by e-beam evaporation technique is studied in this work. Variation in magnetoresistance obtained by I–V measurements at 77 K and in the presence of less than 5 mT magnetic field applied in parallel to the surface is investigated. We have found that this structure exhibit large magnetoresistance in low magnetic fields (i.e. <5 mT). Our results also indicate that the variation in magnetoresistance in the presence of external magnetic field has oscillatory behavior and has the maximum value of 3295%. This structure due to its high sensitivity to low magnetic fields can also be used as an active element in magnetic field sensor devices.

Keywords:Cu–Pt structure; Low magnetic field sensor; I–V curve; Large magnetoresistance

*Correspond Auther:  h_hajghassem@sbu.ac.ir

DOI :10.1016/j.jmmm.2009.