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

TL;DR

This study investigates the electrical conduction properties of Ti/TiOx/Ti structures at low temperatures and high magnetic fields, revealing a two-channel conduction model, a crossover in hopping mechanisms, and minimal magnetoresistance, suggesting potential cryogenic sensor applications.

Contribution

The paper introduces a detailed analysis of Ti/TiOx/Ti structures' conduction mechanisms at cryogenic temperatures and high magnetic fields, highlighting a crossover in hopping conduction and minimal magnetoresistance.

Findings

Conductance explained by parallel hopping and metallic channels.

Observed crossover from Mott to Efros-Shklovskii hopping.

Magnetoresistance remains very small up to 9 T.

Abstract

We present results of electrical conduction studies of Ti/TiOx/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.