Using magnetic structure of Co40Pd60/Cu for the sensing of hydrogen.

Authors :: Jaw-Yeu Liang
Yun-Chieh Pai
Tu-Ngoc Lam
Wen-Chin Lin
Ting-Shan Chan
Chih-Huang Lai
Yuan-Chieh Tseng
Source :: Applied Physics Letters; 7/10/2017, Vol. 111 Issue 2, p1-5, 5p
Publication Year :: 2017
Abstract: This paper reports on a magnetic device with a [Co<subscript>40</subscript>Pd<subscript>60</subscript>/Cu]<subscript>10</subscript> /Fe structure for use in the detection of H<subscript>2</subscript>. In a magneto-optical, transport, and gas-detection system, the proposed device presented sharp, reproducible H<subscript>2</subscript>-dependent magnetic/electrical properties. The device's saturation magnetization (induced resistance change) dropped (increased) by a factor of ~5 when a H<subscript>2</subscript> pressure of 75 kPa is given. Besides, the electrical signal-to-noise ratio of the device can be restored ~50% by exposing it to a magnetic field of 1000Oe, even when the sensitivity of the device dropped at a low H<subscript>2</subscript> pressure (0.7 KPa). This demonstrates the applicability of the device for use as a low-pressure H<subscript>2 </subscript>detector. Operando x-ray spectroscopy revealed that changes in H<subscript>2</subscript>-induced magnetism arose from a Co-Pd charge transfer effect coupled to changes in the local-structure symmetry. [ABSTRACT FROM AUTHOR]