Magnetics Business & Technology - Fall 2013 - (Page 14)

MAGNETS • MATERIALS • MEASUREMENT comes smaller (the crystal moves closer to becoming cubic), the magnetic state of the crystal switches from non-magnetic to a Materials scientists at the US Department of Energy’s (DOE) state with 1.3 Bohr magnetons per Co atom.” Ames Laboratory have found an accurate way to explain the mag- This new understanding may help the further development of netic properties of a compound that has mystified the scientific these materials, which are easily reduced to nanoparticles; these are finding use in catalytic oxidation and reduction reactions assocommunity for decades. ciated with regulation of noxious emissions from motor vehicles. The compound of lanthanum, cobalt and oxygen (LaCoO3) has been a puzModel 121 Programmable DC Current Source zle for more than 50 years, Enables Cost-Effective Sensor Testing due to its strange behav Lake Shore has added its Model 121 programmable DC curior. While most materials rent source to its family of products to support precision test tend to lose magnetism at and measurement. The Model 121 will replace the existing higher temperatures, pure Model 100, 101, 102, 110 and 120 current sources, offering LaCoO3 is a non-magneta singular, easy-to-use instrument with expanded capabilities ic semiconductor at low and upgraded performance. temperatures, but as the The Model 121 current source is intended for testing, measurtemperature is raised, it being, and operating resistive and semiconductor devices such as comes magnetic. With the diodes. It provides a convenient and reliable alternative to simple addition of strontium on voltage-based circuits, and an affordable alternative to more exthe La sites the magnetic pensive multi-function current sources. It is suitable for benchproperties become even top use or panel-mounted operation in labs, test facilities and more prominent until, at manufacturing environments in applications such as magnetic 18 percent strontium, the Bruce Harmon (left) and Youngbin Lee and temperature sensor compound becomes metalcalibration, sensor and lic and ferromagnetic, like iron. semiconductor device “It’s just strange stuff. The material has attracted a lot of atten- QC, LED brightness testtion since about 1957, when people started picking it up and re- ing, semiconductor deally studying it,” said Bruce Harmon, senior scientist at the Ames vice characterization, and Laboratory. “Since then, there have been more than 2,000 perti- Lab electrochemistry. nent papers published.” The Model 121 pro Traditional theories to describe the compound’s behavior origi- vides a low-noise, stable nated with physicist John B. Goodenough, who postulated that DC current source with as temperature rises, the spin state of the d-electrons of cobalt six decades of output current, operator-selectable or programchanges, yielding a net magnetic moment. mable from 100 nA to 100 mA, large three digit LED display and “Back then it was more of a chemist’s atomic model of elec- simple user interface, USB interface for integration with autotron orbits that suggested what might be going on,” explained mated test systems, and DIN panel mountable package. Harmon. “It’s a very local orbital picture and that theory has The programmable feature of the model provides improved persisted to this day. It’s become more sophisticated, but almost operability, allowing the user to define application-specific test all the theoretical descriptions are based on that model.” currents and change current output automatically through a con But when Ames Laboratory research partners at the Argonne nected PC. Programming is done via a USB serial interface, and National Laboratory and the University of California, Santa Cruz LabVIEW drivers will be available later this year. The model is performed X-ray absorption spectroscopy measurements of the also CE and RoHS certified. material, the theory didn’t fit what they were observing. “This new current source offers our industrial and research “They knew that we could calculate x-ray absorption and mag- customers the precision, dependability and convenience needed netic dichroism, so we started doing that. It is a case where we fell for test and measurement work,” said David Plaga, Lake Shore’s into doing what we thought was a routine calculation, and it turned instrument product manager. “It’s inexpensive, simple to use, and out we discovered a totally different explanation,” said Harmon. adds power and versatility to the lab bench.” “We found we could explain pretty much everything in really nice detail, but without explicitly invoking that local model.” Development Board for Xtrinsic Sensors The scientists found that a small rhombohedral distortion of Now Available the LaCoO3 lattice structure, which had largely been ignored, Newark element14 has launched its multi MEMS development was key. board for Xtrinsic sensors, a low cost enablement solution that al “We found that the total electronic energy of the lattice depends lows designers to understand and test the latest sensing technolosensitively on that distortion,” said Harmon. “If the distortion begies with a next generation accelerometer, pressure sensor and Scientists Solve Riddle of Strangely Behaving Magnetic Material 14 Magnetics Business & Technology • Fall 2013 www.MagneticsMagazine.com http://www.MagneticsMagazine.com

Table of Contents for the Digital Edition of Magnetics Business & Technology - Fall 2013

Editor's Choice
Nanocrystalline Materials for the Next Generation of Noise Suppression Solutions
Magnetic Continuously Variable Transmission
Magnets • Materials • Measurement
Simulation Accuracy Helps Pioneering Superconducting Generator Developments
Application • Component Developments
Research & Development
Industry News
Marketplace/Advertising Index
Spontaneous Thoughts: NdFeB: The First 30 Years and the Next 30 Years

Magnetics Business & Technology - Fall 2013