Technical and Scientific Impact

1. Strong, Ductile and Low-Field Magnetostrictive Alloys Based on Fe-GaSivaraman Guruswamy, University of UtahDMR 0241603 • Research Focus • Magnetostriction refers to the change in the length of a material when a magnetic field is applied. Ga addition dramatically increases the magnetostriction of Fe. FeGa based alloys with attractive combinations of low hysteresis, low saturation field, good mechanical properties, and low cost developed for use in sensor and actuators applications • Research focuses on developing a fundamental understanding needed to develop other low cost Fe based magnetostrictive alloys, and low cost processing methods. • Significant Findings • Ga addition dramatically increases the magnetostriction of Fe. Large substitutions of Ga with Al and Be can be made in Fe-20 at% Ga alloys while retaining large magneto-striction. Optimal FeGaAl compositions identified. • A safe technique for preparing FeBe alloys was developed. • Inexpensive and simple thermo-mechanical processing method developed for [001] textured Fe-15 at.% Ga alloys • The effect of solute additions on the magnetostriction of Fe arises mainly from changes in local atomic environment, and the effect due to image stresses is less significant. • Formation of all long range ordered phases can be avoided through careful process control. Addition of Al can be used to suppress the L12 and DO19 ordering in FeGa alloys. • Short range ordering enhances the magnetostriction Large magnetostriction in Directionally Grown Fe-27.5 at.% Ga alloy • Technical and Scientific Impact • Improved understanding of magnetostriction and ordering in FeGa alloys developed. • The laboratory selected as a 2005 State of Utah Center of Excellence in Magnetic Sensor and Actuator MaterialsStoel Rieves Innovation award finalist, Salt Lake City, 2006 • FeGa alloys being considered for numerous sensor and actuator applications such as sonic and ultrasonic devices, nanovalves, load sensors, ABS, and active damping devices 200 lattice imageand [110]electron diffraction pattern of ” orderedFe-27.5 at.% Ga. [110] ZA Diffuse scattering in the low angle region arising from short range ordering in FeGa alloys. Correlation with available magnetostriction data suggests increased magnetostriction with short range ordering. (001) Pole figure showing strong [001] texture in TMP Fe-15 at.% Ga alloy

2. Strong, Ductile and Low-Field Magnetostrictive Alloys Based on Fe-GaSivaraman Guruswamy, University of Utah DMR 0241603 • Education and Training • Eight graduate students (Four PhD and four MS) and three undergraduates have been supported. Five have presented papers in the national meetings. • All students are trained in advanced processing and characterization techniques including single crystal growth, OIM in SEM, TEM, XRD, magnetic and magnetostriction measurements, and Resonant Ultrasound Spectroscopy • Students built nanopositioning and ultrasonic device prototypes • Undergraduate student Rebecca Chandler presented a poster paper on “The influence of ordering on magnetostriction” at the Univ. of Utah Undergraduate Research Conference and was a co-author of the paper presented at the TMS Annual Meeting • Students in Physical Metallurgy, Magnetic Materials, and Materials Design classes exposed to MML and ongoing research Robert Corson attending the 54th Annual Meeting of Students with the Nobel Laureates in Lindau Germany, during June-July 2004 Rebecca Chandler presenting a poster at the Undergraduate Research Conference • Outreach Activities • Robert Corson was selected as a member of the US student delegation to the 54th Annual Meeting of Students with the Nobel Laureates in Lindau Germany, held during June-July 2004 • The PI and the graduate students showcased the Magnetic Materials Laboratory to well over 250 high school students, middle school students, and parents during the Science days, Open-houses, and other arranged and informal visits • Technological Innovation Showcase meetings in 2003, 2004,2005 and 2006 in Salt Lake City, and State Technology Showcase in 2005. Open to public. • Over 18 presentations, 24 Journal/conference papers, 3 PhD and 3 MS publications Middle school students from Youth Teaching Youth program with Prof. Guruswamy outside MML clean room High School Students and parents watching the demonstration of a magnetostrictive ultrasonic device • Over 18 invited and contributed presentations, 5 Journal papers (3 in print and 2 in review), 15 Proceedings papers, 2 PhD dissertations, and 1 MS thesis Graduate studens Swieng and under-graduate Gavin testing a single crystal growth system Graduate student Pinai helping undergraduate Rebecca Chandler with magnetic measurements using a VSM

3. Strong, Ductile and Low-Field Magnetostrictive Alloys Based on Fe-GaSivaraman Guruswamy, University of Utah DMR 0241603 Fe-Ga alloys show the highest values of magnetostriction in disordered bcc form. Magnetostriction decreased slightly on extended ordering treatment in ” range. DO19 and L12, ordering decrease magnetostrictionto nearly zero or a small negative value. The figures show [200] lattice image and [110] electron diffraction pattern for ” orderedFe-27.5 at.% Ga Diffuse X-ray scattering in the 10-40 ° region arising from short range ordering (SRO). Correlation with available magnetostriction data suggests increased magnetostriction with increase in SRO. Fe-Zn and other binary iron alloys are being studied to gain improved understanding of magnetotriction and develop new low cost alloys. Powder metallurgy processing involving explosive compaction is used to obtain full density FeZn alloys. Figure on the right shows an x-ray tomography image of a section in an as-explosively compacted Fe-Zn sample prepared for magnetostriction studies. The image is 5.4 x 4.5 mm in size. Full density regions and regions with cracks and central porosity resulting from high compaction pressures can be seen. (a) (b) Zn KX-ray map ofFe-30 at.% Zn alloy (a) before and (b) after homogenization anneal