The useful properties of chemical compounds are determined by the elements from which they are made and the arrangement of the atoms. However, there are often several ways atoms of the same elements can be arranged to form a solid. Wisconsin MRSEC researchers are particularly interested in a series of compounds formed from rare-earth elements and iridium. One phase, Pr2Ir2O7, is of particular interest because it exhibits novel magnetic phenomena and can open new opportunities in the field of quantum materials.
The crystallization of complex oxides can be templated by a crystalline seed. Nanoscale crystallization environments lead to the possibility that this process can be employed to create precise arrays of nanoscale materials for electronic, magnetic, and optical applications.
Recent Chemistry doctoral graduate, Tesia Janicki, was awarded the Wisconsin Initiative for Science Literacy (WISL) Award for Communicating PhD Research to the Public. Her chapter in her PhD thesis, “Atomistic computational approaches in molecular models and inorganic crystallization,” is a series of cartoons explaining key concepts of chemistry and of Janicki’s doctoral work.
A team of researchers from the Wisconsin Materials Research Science and Education Center (MRSEC) at the University of Wisconsin–Madison has designed, constructed, and implemented a new, highly specialized piece of research equipment that can be used to visualize the real-time formation and growth of tiny crystals of novel materials. The unique perspective provided by this approach provides access to new ways to discover and develop materials relevant to electronics, optics, and magnetic applications.
Engineers currently lack good substrate materials on which to grow thin films of materials like GaN with few defects. These layers are needed in applications like high-power transistors and solid-state lighting. Available bulk crystals have the wrong crystal structure or the wrong distance between the atoms. The Wisconsin MRSEC has developed a buffer layer material and related synthesis method that promises to alleviate the substrate problem.
The Wisconsin MRSEC has created thin films of a fascinating magnetic material, Pr2Ir2O7, in which the magnetic moments are frustrated: No matter how they are arranged, some of the moments are always fighting to change their direction, like two bar magnets with their north poles shoved together. Frustration creates a rich landscape for discovery and manipulation of new magnetic effects and of electronic phenomena linked to magnetism.
Researchers at the Wisconsin MRSEC have developed a new instrument using very bright synchrotron x-ray beams to watch nanoscale crystals as they grow. The system has a unique design that allows the crystals to grow in vacuum while keeping the x-ray lenses and the x-ray beam in air but bringing them very close to the crystal. Wisconsin MRSEC researchers are using this new instrument to learn about solid phase epitaxy, a process based on the growth of ordered crystals from a disordered amorphous solid, which is capable of creating new materials for applications in electronics, optics, sensors, and quantum information.
Yajin Chen presented her work on the use of solid-phase epitaxy to create epitaxial complex-oxide interfaces that have promising electronic properties at the APS March Meeting 2019 in Boston, MA.
Peng Zuo, a postdoc working in the MRSEC IRG 2, presented his group’s work on the system of PrAlO3/SrTiO3 created by solid phase epitaxy at the International Conference on Crystal Growth and Epitaxy (ICCGE-19) in …
Highlighting her recent work with the MRSEC Interdisciplinary Research Group on Complex Metal Oxides, graduate student, Tesia Janicki, brought home an award for best poster from the 51st Midwest Theoretical Chemistry Conference (MWTCC) in June.