Positive Magnetoresistance in Amorphous Ni–CN$_{x}$/p-Si Heterostructure

Abstract

Current-perpendicular-to-plane transport properties of amorphous Ni–CNx/p-Si heterostructure have been investigated. In the reverse range, where the electrons are injected from the amorphous Ni–CNx to p-Si, the positive magnetoresistance (MR) can be attributed to the formation of a spin-polarized barrier by the exchange interaction between electrons in the accumulation electron layer in Si and d electrons of Ni, which is further confirmed by the temperature-peak-type MR. In the forward range, where the electrons are injected from p-Si to the amorphous Ni–CNx, a positive MR of ∼90% is observed at 100 K under a 0.01-mA current and a 90-kOe magnetic field, which may be related to the peak in the resistance-to-current curves around 0.01 mA at low temperatures.

Positive magnetoresistance in Co 40 Fe 40 B 20 /SiO 2 /Si heterostructure

“…high processing speed at low power [6,16]. Magneticfield-controlled MR effects have been widely reported in ferromagnet/semiconductor heterostructures, such as Fe 3 O 4 /Si [7,8], Fe 3 O 4 /Nb:SrTiO 3 [9], Co/Si [10], granular films/Si [11,12], LaSrMnO 3 /Si [13], InMnSb/InSb [14], InMnAs/InAs [15]. It is generally accepted that MR in such heterostructures was usually related to the Zeeman effect induced by spin-splitting bands [14,15], charge ordering transition in ferrite [7,8], magnetic-fieldcontrolled process of impact ionization [11,12] or antiferromagnetical coupling between magnetic layer and interfacial layer in semiconductors [10].…”