Bulk combinatorics and high throughput assessments for accelerated development of magnetic alloys
Matthew Kramer, Ph.D.
Director, Division of Materials Science & Engineering
Ames Laboratory, Iowa
Combinatoric synthesis combined with high throughput characterization has impacted materials discovery in a number of fields. For many inorganic systems, thin film deposition is an ideal platform since large chemical spreads can be put down on a single substrate. Unfortunately for many materials, the bulk properties are not reflected in their thin film analogues. Laser-based, direct feed advanced manufacturing (e.g., 3D printing) provides a robust means of quickly producing a wide range of compositions in bulk form. Using Optomec’s Laser-Engineering-Net-Shape (LENS) system, we can produce about 30 samples per hour in a wide range of compositions in a very well controlled inert atmosphere. These samples, in turn, need to be evaluated rapidly in terms of their phase assemblages. A Netsch differential scanning calorimeter and thermogravimetric analysis autosampler allows up to 20 samples to be analyzed in ~24 hours. A Bruker Tornado micro X-ray fluorescence (XRF) system can provide quantitative chemical analysis in a matter of a few minutes per sample. For magnetic characterization we have adapted our Quantum Design vibrating sample magnetometer with a 6 sample changer. To more fully map out the phase space, we have been developing the capability to heat multiple samples in a controlled atmosphere while taking X-ray diffraction and XRF at the Stanford Synchrotron Research Facility. Acquisition times for a full XRD spectra takes about 5s. We are currently working on robust data analytics to assemble and analyze these large data sets. Maintaining and disseminating such large data sets with disparate formats remains a challenge. A few specific examples in promising permanent magnet alloy systems will be presented.
Dr. Matthew Kramer is the director of the Materials Science and Engineering Division at the US Department of Energy’s Ames Laboratory Materials. He is also an Adjunct Associate Professor of Materials Science and Engineering at Iowa State University. He has received his Ph.D. and M.S. degrees in Geology from Iowa State University (1989) and University of Rochester (1983), respectively. Research interests include materials characterization using advanced electron beam and synchrotron X-ray methods connecting synthesis to advanced modeling through in situ and in operando studies. Materials of interest include amorphous metals and their liquids, functional materials (permanent magnets, thermal electrics) and high temperature alloys.