MIXED-VALENT TRANSITION METAL OXIDES Mas A. Subramanian, Oregon State University, DMR 0804167

1. MIXED-VALENT TRANSITION METAL OXIDESMas A. Subramanian, Oregon State University, DMR 0804167 • This is an exploratory research on the identification, synthesis, and characterization of new mixed-valent metal oxides with possible charge ordering. The cations involved in charge ordering are transition metal cations with unpaired electrons; thus, coupling between electrical and magnetic properties is anticipated. In addition to multiferroic properties (dielectric and magnetic properties), the new compounds synthesized under this program are also screened for various phenomena such as superconductivity, magnetoresistance, thermoelectricity, non-linear optics, etc. • Several hitherto unknown mixed-valent rhodium oxides have been discovered. • Charge-ordering is rare in Rh-oxides – Bi6Rh12O29 shows partial charge ordering. • Discovered first Verwey-type transition in Pb3Rh7O15. • BiLi2Rh6O12 and Ln2/3Rh2O4showed high electronic conductivity and large Seebeck coefficients and are promising candidates for thermoelectric applications. • New BVS (Ro) parameters for Rh3+/Rh4+ determined Bi6Rh12O29 Pb3Rh7O15 BiLi2Rh6O12 Ln2/3Rh2O4

2. MIXED-VALENT TRANSITION METAL OXIDESMas A. Subramanian, Oregon State University, DMR 0804167 • This program is providing training for both undergraduate and graduate students in synthetic materials chemistry, crystal structure analysis and electronic properties. This program also provides these students with the intellectual challenge of understanding the complex behavior of newly synthesized materials and help forge links between chemistry, physics and material science. • The high school portion of the outreach program is being conducted in conjunction with the successful ASE (Apprenticeships in Science and Engineering) portion of the Saturday Academy Program. So far, four high school students participated in this program (2008, 2009). The ASE organization helped to recruit potential scientists from regional high schools to participate in this program • Students participating in this research program is gaining experience that will prepare them well for the modern academic and industrial environments. 10th Graders Aida Behmard (Salam High school) and Nathan Lazaroff (Corvallis High School) testing phosphors and superconductors they made in PI laboratories during their stay in the summer of 2009.