Susan M. Kauzlarich

Professor

Tel: (530) 752-4756

Fax: (530) 752-8995

Email: smkauzlarich@ucdavis.edu

NSF Solid State Chemistry and Materials Workshop 2002, 1998

IGERT webpage

Inorganic and Materials Chemistry

B.S., College of William and Mary, 1980. Ph.D., Michigan State University, 1985. Postdoctoral Associate, Iowa State University, 1985-87. Appointed to faculty, UC Davis, 1987-. Maria Goeppert Mayer Distinguished Scholar Award from Argonne National Laboratory 1997. Visiting Scholar, Argonne National Laboratory, 1997-1998. 2001-2002 Outstanding Mentor Award from the UCD Consortium for Women and Research.  2005 UC Davis Distinguished Graduate Mentoring Award.

Research Interests

Solid-state and materials chemistry. Synthesis and characterization of new materials. Novel magnetic and electronic materials. Synthesis and characterization of nanoclusters.

The search for new materials with novel structures and properties is the primary focus of my research. Fundamental research on bulk materials has lead to the discovery of the ternary molybdenum chalcogenides, ternary metal borides and most recently multi-ternary copper oxides. The superconducting ternary chalcogenides have been shown to have very high critical magnetic fields, the ternary metal borides are the strongest magnets known and research on multiternary copper oxides has lead to the discovery of high temperature superconductivity. These three recent examples of new compounds with exciting properties have had a global impact and will continue to change the state of science and technology in many different fields. Three different projects on solid-state chemistry and new materials are outlined below.

Zintl Phases

Although in many cases, the discovery of new materials is accidental, rational approaches to solid state synthesis have been proposed and may lead to a large number of new compounds. This group has successfully employed electron counting rules known as the Zintl-Klemm rules and have extended them to the design and synthesis of new ternary and multiternary transition metal pnictides. There are a wide variety of ternary compounds, A_xM_yX_z, where A = alkali or alkaline earth metal, and M, X = semimetal or main group element. The bonding in these compounds can be understood according to the Zintl or Zintl-Klemm concept. The electropositive element donates its electrons to the more electronegative elements which, in turn, form homo- or heteroatom bonds so that the 8-N rule is satisfied. One objective of this research is to synthesize new ternary compounds of the type A⁺ + [(MX)^-], where M is now a transition metal. These new compounds can be considered Zintl compounds if the d electrons are localized on the metal and the bonding description remains the same as the main group analogs. This strategy for the synthesis of solid state compounds is unique and is a directed synthetic effort. It has provided new transition metal compounds (A₁₄MnX₁₁ (A = Ca, Sr, Ba, E, Yb; X = P, As, Sb, Bi)) which have unique magnetic and electronic properties. These compounds contains Mn^IIIX₄^9- tetrahedra and X₃^7- linear units and the structure is shown in below. In addition to these unusual polyatomic units in this structure, these materials are ferromagnetic even though the minimum distance between Mn atoms is ~10 Å. Our research, along with others in this field, have shown that magnetic Zintl phases reveal interesting thermoelectric, colossal magnetoresistance, and ferromagnetic (while being electronically insulating) properties, as well as other unusual magnetic phenomenon worth exploring. The goals of this study are to provide structure-property correlation for thermoelectric Zintl phases, exploratory research on light element and magnetic Zintl phases, and also to advance the field of solid state chemistry.

We are interested in new materials for energy applications, both thermoelectric materials and hydrogen storage materials.  

Thermoelectric devices are a significant part of the solution to today’s energy problems; they convert thermal energy directly into electrical energy, are environmentally benign, require minimal maintenance, and can be operated over a large temperature range (room temperature to 1000˚C).  While there are many approaches to solving energy problems, the recent discovery of a high ZT material (where zT = figure of merit; higher the value, greater the efficiency), Zn₄Sb3, a Zintl-like valence compound, provides incentive for studying the thermoelectric properties of other complex antimonide Zintl phases.  Many Zintl phases possess hallmarks for good thermoelectric properties.  We are also exploring light element containing Zintl phases for thermoelectric applications.  These types of materials maybe important for applications involving transportation or light weight power sources. 

Light element nanoparticles for hydrogen storage.  The project is concerned with reversible hydrogen storage by small nanoparticles of silicon (Si), and other light element alloy nanoparticles. These materials have the potential of reaching 9.0 % hydrogen by weight, depending upon nanoparticle size and surface coverage.  This project offers new nanomaterials for hydrogen storage that are relatively inexpensive and available.  Preliminary work suggests that the synthetic routes are feasible. The long term goal is to obtain viable materials with potential hydrogen capacity greater than 10 wt% and demonstrate reversible hydrogenation/dehydrogenation capability to meet DOE 2010 system-level targets.

Nanoparticles

Publications

Chemistry, Structure and Bonding of Zintl Phases and Ions S. M. Kauzlarich, Ed., VCH Publishers, New York. 1996

Bley, R. A. and S. M. Kauzlarich. 1996. A low temperature solution phase route for the synthesis of silicon nanoclusters. Journal of the American Chemical Society, 118, 12461-12462.

Chan, J.Y., S. M. Kauzlarich, P. Klavins, R. N. Shelton, and D. J. Webb. 1997. Colossal magnetoresistance in the transition metal Zintl compound Eu₁₄MnSb₁₁, Chemistry of Materials,  9, 3132-3135.

Baldwin, R. K., Pettigrew, K. A., Ratai, E., Augustine, M. P., and Kauzlarich, S. M. 2002.  Solution Reduction Synthesis of Surface Stabilized Silicon Nanoparticles, Chemical Communications, 1822-1823.

Pettigrew, K. A., Liu, Q., Power, P. P., and Kauzlarich, S. M. 2003. Solution Synthesis of Alkyl- and Alkyl/Alkoxy-Capped Silicon Nanoparticles via Oxidation of Mg₂Si, Chemistry of Materials, 15, 4005-4011. 

Zou, J.,  Baldwin,  R. K., Pettigrew, K. A., and Kauzlarich, S. M. 2004.  Solution Synthesis of Ultrastable Luminescent Siloxane-coated Silicon Nanoparticles, Nano Letters, 4, 1181-1186.

Cho, S.-J., Idrobo, J.-C., Olamit, J., Liu, K., Browning,  N. D., and Kauzlarich S. M..  2005.  Growth mechanisms and oxidation resistance of gold-coated iron nanoparticles, Chemistry of Materials, 17, 3181-3186.