Faculty Directory

Applications of combinatorial synthesis and characterization methodology to electronic, magnetic and smart materials; fabrication and characterization of novel multilayer thin-film devices; machine learning for materials science, caloric cooling materials and devices

Combinatorial Investigation of Functional Materials

We have developed a comprehensive methodology for rapid mapping of previously unexplored compositional landscape in search of novel multifunctional materials. A variety of thin film deposition tools are implemented for synthesis of combinatorial thin film libraries and composition spreads of various designs. A suite of rapid characterization tools are utilized for quantitative mapping of relevant physical properties across combinatorial libraries. These include microwave microscopes, a scanning magneto-optical Kerr measurement setup and scanning x-ray diffractometers. Current topics of interest include magnetistrictive materials, multiferroic materials, and shape memory alloys. Our recent emphasis has also been on development of informatics techniques to effectively handle, visualize, and analyze the large amount of data which are generated from the combinatorial experiments. We have a network of international collaborators with whom a number of combinatorial experiments are carried out at any given time.

Learn more about combinatorial materials science

• See also:
  • The W. M. Keck Laboratory for Combinatorial Nanosynthesis and Multiscale Characterization
  • CNAM: The Center for Nanophysics and Advanced Materials
  • Research Spotlight: Combinatorial Synthesis: A New Method of Discovery

Novel Multilayer Thin Film Devices

Previously I had worked on fabrication and characterization of superconducting thin film devices for over 10 years. My interest in novel functional devices now spans a range of other materials including magnetic materials and various smart materials. Our current projects include various multilayer multiferroic devices.

Scanning Probe Microscopy

Many of the rapid characterization tools used for screening combinatorial libraries are scanning probe microscopes. For instance, we work extensively with scanning SQUID microscopes (in collaboration with Neocera, Inc.) and scanning microwave microscopes. We have recently demonstrated high sensitivity scanning magnetic probe microscopy using a magnetoelectric device. Our current project includes development of novel microwave microscopy combined with atomic resolution STM for performing spin resonance measurements.

Current and Recent Group Members Include:

• A. Gilad Kusne (NIST)
• Valentin Stanev

• Xiaohang Zhang
• Tieren Gao

• Heshan Yu
• Rohit Pant

Graduate Students

• Jihun Park
• Haotong Liang
• Felix Adams
• Chih-Yu Lee
• Ricmond Wang
• Boyang Liu
• Thomas Wong
• Logan Saar
• Dylan Kirsch
• Samuel Freed
• Sabrina Curtis
• Justin Pearson

Undergraduate Students

ENMA 460/PHYS 431 Introduction to Solid State Physics

ENMA 437/637 Machine Learning for Materials Science

ENMA 481 Electronic and Optical Materials

ENMA 465 Microprocessing

Publications list

For a closer look at our research, take a look at the video links below:

• Made of Star Stuff - PhD Student Justin Pearson, advised by Prof Takeuchi, discusses his thin film research.
• Robot (Materials) Science: Can Watson Beat Edison?
• Combinatorial Time Lapse
• Dwight Quench: We have developed a technique where an entire thin film on a wafer can be quenched from a high temperature. In the movie, a thin-film composition spread wafer mounted inside a narrow high-vacuum chamber pumped by a cryopump is annealed in a furnace at 800 C. For quenching the wafer, it is “quickly” pulled out of the furnace, and the chamber is dunked in an ice bucket. This results in formation of quenched thin film phases as reported in Ref. 102, Applied Surface Science 254, 725 (2007) and Ref. 147, Nature Communications 2, 518.
• FeCoNi XRD contourslices-2: Visualization of X-ray diffraction patterns from the entire Fe-Co-Ni composition spread. The big triangular shaped blob corresponds to the main fcc peak showing significant shift as a function of composition. The thin oval blob near the Fe end is the bcc main peak. Shown on the cover of Ref. 95.
• IchiroCombi with Targets: Combinatorial pulsed laser deposition of epitaxial oxide thin films. The movie shows the synthesis process of an epitaxial composition spread onto a heated substrate. Two targets (with end compositions) are used to deposit alternating ultrathin gradient thickness wedges using a synchronized moving shutter gliding over the substrate. The thickness of the wedge is designed to be less than a unitcell. The deposition of hundreds of wedges results in mixing of the end compositions at the unitcell level during the deposition at an elevated temperature. The composition continuously varies on the substrate from one end composition to the other. Each composition spread sample is roughly 7-10 mm long. This technique is used for continuous substitution experiments. See for instance, Ref. 71,72, 85, 100.
• XRDSuite: demo of early combinatorial X-ray diffraction data visualization and analysis tool. One can see a large number of diffraction patterns in a number of different ways.
• NiMnAl – Sepctrum Scroller: Another demo movie of XRDSuite.
• NiMnAl – Peak Plotter (Full Spectrum with Mag): Comparison of diffraction patterns of Ni-Mn-Al composition spread and magnetism. With one look, one can see which diffraction peaks (and phases) are responsible for the composition regions with strong remnant magnetization (measured by scanning SQUID).
• Demo of CombiView: software to carry out rapid visualization and cluster analysis of a large number of diffraction patterns taken from combinatorial libraries.