Electrical conduction of Ti/TiO_x/Ti structures at low temperatures and high magnetic fields

Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice, Slovakia

^a e-mail: batkova@saske.sk

Received: 20 November 2015
Revised: 9 February 2016
Accepted: 11 February 2016
Published online: 9 March 2016

Abstract

We present results of electrical conduction studies of Ti/TiO_x/Ti planar structures prepared by tip-induced local anodic oxidation (LAO) of titanium thin films. The prepared structures have shown almost linear I-V curves at temperatures between 300 K and 30 K, and only slight deviation from linear behaviour at lower temperatures. Electrical conductance of the structures can be adequately explained by a two-channel model where variable range hopping channels and metallic ones coexist in parallel, while a crossover from Mott to Efros-Shklovskii variable-range-hopping conductivity has been observed at decreasing temperature. The magnetoresistance of the studied structures is very small even in magnetic fields up to 9 T. The reported electrical properties of the structures indicate their promising applications as very low heat capacity temperature sensors for cryogenic region and high magnetic fields.