Nearest neighbour hopping conductors with negative magnetoresistance

A.B. Pakhomov, D.S. McLachlan, I.I. Oblakova and A.M. Virnik

Physica A: Statistical Mechanics and its Applications, 1994, vol. 211, issue 4, 393-398

Abstract: DC resistance and magnetoresistance measurements are performed on insulating AlAl2O3 samples which are prepared from conducting metal-insulator granular composite samples by subjecting them to high density current pulses. This treatment drastically reduces the room-temperature conductivity of the mixture, due to the explosion of a fraction of the metallic grains in percolation channels. Providing the pulse current density is high enough, the samples show the hopping conductivity. Two distinctly different nearest-neighbour hopping (NNH) types of samples may be obtained. In the first (M) type samples, conduction is dominated by hopping between adjacent metallic grains imbedded in a dielectric host medium. Negative orbital magnetoresistance (NMR), with a quasilinear field dependence, is observed at both 77 and 300 K. In the samples of the second (H) type (those which have been subjected to higher current pulses or to several sequential pulses of the same amplitude), conduction is found to be dominated by NNH between single impurity atoms. Positive magnetoresistance is now observed.

Date: 1994
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/0378437194001324
Full text for ScienceDirect subscribers only. Journal offers the option of making the article available online on Science direct for a fee of $3,000

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:phsmap:v:211:y:1994:i:4:p:393-398

DOI: 10.1016/0378-4371(94)00132-4

Access Statistics for this article

Physica A: Statistical Mechanics and its Applications is currently edited by K. A. Dawson, J. O. Indekeu, H.E. Stanley and C. Tsallis

More articles in Physica A: Statistical Mechanics and its Applications from Elsevier
Bibliographic data for series maintained by Catherine Liu ().