Vanadium dioxide research opens door to new, multifunctional spintronic smart sensors

Feb 05, 2014 by Matt Shipman

Research from a team led by North Carolina State University is opening the door to smarter sensors by integrating the smart material vanadium dioxide onto a silicon chip and using lasers to make the material magnetic. The advance paves the way for multifunctional spintronic smart sensors for use in military applications and next-generation spintronic devices.

Vanadium dioxide is currently used to make . By integrating the material as a single crystal onto a silicon substrate, the researchers have made it possible to create infrared , in which the sensor and computational function are embedded on a single chip. This makes the sensor faster and more energy efficient, since it doesn't have to send data to another chip to be processed. Smart sensors are also lighter than conventional ones, since separate chips aren't necessary.

"For , sensor technology needs to be able to sense, manipulate, and respond to data quickly – and this work achieves that," says Dr. Jay Narayan, John C. Fan Distinguished Chair Professor of Materials Science and Engineering at NC State and senior author of a paper describing the work.

In addition, the researchers used high-power nanosecond-pulsed laser beams to modify the and make it magnetic. This will allow the creation of spintronic smart sensors that incorporate infrared sensors and magnetic sensors on a single chip. Spintronics refers to technologies used in solid-state devices that take advantage of the inherent spin in electrons and their related magnetic momentum. The potential advantages of spintronics include higher memory capacity, faster data transfer and more computational power on a computer chip.

Explore further: Researchers integrate single-crystal BFO onto a silicon chip, open door to smart devices

More information: The paper, "Diamagnetic to ferromagnetic switching in VO2 epitaxial thin films by nanosecond excimer laser treatment," is published online in Applied Physics Letters. scitation.aip.org/content/aip/… 25/10.1063/1.4857155

Abstract
VO2(010)/NiO(111) epitaxial heterostructures were integrated with Si(100) substrates using a cubic yttria-stabilized zirconia (c-YSZ) buffer. The epitaxial alignment across the interfaces was determined to be VO2(010)‖NiO(111)‖c-YSZ(001)‖Si(001) and VO2[100]‖NiO(110)‖c-YSZ(100)‖Si(100). The samples were subsequently treated by a single shot of a nanosecond KrF excimer laser. Pristine as-deposited film showed diamagnetic behavior, while laser annealed sample exhibited ferromagnetic behavior. The population of majority charge carriers (e−) and electrical conductivity increased by about two orders of magnitude following laser annealing. These observations are attributed to the introduction of oxygen vacancies into the VO2 thin films and the formation of V3+ defects.

Related Stories

Recommended for you

Atomic trigger shatters mystery of how glass deforms

Oct 18, 2014

Throw a rock through a window made of silica glass, and the brittle, insulating oxide pane shatters. But whack a golf ball with a club made of metallic glass—a resilient conductor that looks like metal—and the glass not ...

Superconducting circuits, simplified

Oct 17, 2014

Computer chips with superconducting circuits—circuits with zero electrical resistance—would be 50 to 100 times as energy-efficient as today's chips, an attractive trait given the increasing power consumption ...

Protons hog the momentum in neutron-rich nuclei

Oct 16, 2014

Like dancers swirling on the dance floor with bystanders looking on, protons and neutrons that have briefly paired up in the nucleus have higher-average momentum, leaving less for non-paired nucleons. Using ...

Cosmic jets of young stars formed by magnetic fields

Oct 16, 2014

Astrophysical jets are counted among our Universe's most spectacular phenomena: From the centers of black holes, quasars, or protostars, these rays of matter sometimes protrude several light years into space. ...

User comments : 0