skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Gas sensor

Patent ·
OSTI ID:1158792

A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC02-05CH11231
Assignee:
The Regents of the University of California (Oakland, CA)
Patent Number(s):
8,826,726
Application Number:
13/318,522
OSTI ID:
1158792
Resource Relation:
Patent File Date: 2010 Apr 29
Country of Publication:
United States
Language:
English

References (11)

Hydrogen-induced reversible spin-reorientation transition and magnetic stripe domain phase in bilayer Co on Ru(0001) journal April 2012
Tunneling magnetoresistive (TMR) sensor having a barrier layer made of magnesium-oxide (Mg-O) patent-application January 2005
Heat assisted switching in an MRAM cell utilizing the antiferromagnetic to ferromagnetic transition in FeRh patent-application December 2005
Device having a structural element with magnetic properties, and method patent-application October 2006
Electrochemical Gas Sensor Chip and Method of Manufacturing the Same patent-application June 2008
Nano ic patent-application November 2006
Concept for Detecting a Change of a Physical Quantity by Means of a Conductor Structure patent-application April 2008
Method and device for carrying out the nondestructive material characterization of ferromagnetic substances patent June 2004
Reversible H-Induced Switching of the Magnetic Easy Axis in N i / C u ( 001 ) Thin Films journal December 2004
Structure and morphology of ultrathinCo/Ru(0001) films journal March 2007
Magnetoresistive Sensor Having a Structure for Activating and Deactivating Electrostatic Discharge Prevention Circuitry patent-application February 2008

Cited By (1)

Gas sensor patent September 2014