Synthesis and characterization of zirconium-antimony binary and interstitial ternary intermetallic compounds

Thumbnail Image
Garcia, Eduardo
Major Professor
Committee Member
Journal Title
Journal ISSN
Volume Title
Research Projects
Organizational Units
Organizational Unit

The Department of Chemistry seeks to provide students with a foundation in the fundamentals and application of chemical theories and processes of the lab. Thus prepared they me pursue careers as teachers, industry supervisors, or research chemists in a variety of domains (governmental, academic, etc).

The Department of Chemistry was founded in 1880.

Dates of Existence

Related Units

Journal Issue
Is Version Of

A family of Zr[subscript]5Sb[subscript]3Z compounds, Z = C, O, Al, Si, P, S, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, have been synthesized in the Mn[subscript]5Si[subscript]3 structure. The Z element occupies the center of confacial trigonal antiprisms of zirconium atoms. Antimony can also occupy the interstitial site, and the binary compound has a homogeneity range Zr[subscript]5Sb[subscript]3.0 to Zr[subscript]5Sb[subscript]3.4.;The compounds were mainly prepared by arc-melting or powder sintering. Temperatures in excess of 1100° C were needed to provide adequate reaction rates for the sintering experiments. Isothermal vapor transport reactions, 1100 < T <1300° C, with iodine as a transporting agent were used to ensure complete reaction, but provided no single crystals. Reactions using Zn or In as a solvent yielded single crystals of a size suitable for physical property measurements. Structural refinements were carried out for the compounds Zr[subscript]5Sb[subscript]3Al, Zr[subscript]5Sb[subscript]3Si, Zr[subscript]5Sb[subscript]3S, Zr[subscript]5Sb[subscript]3Fe, Zr[subscript]5Sb[subscript]3(Fe[subscript]2/3In[subscript]1/3).;Extended-Huckel band calculations were carried out on Zr[subscript]5Sb[subscript]3, Zr[subscript]5Sb[subscript]3S, and Zr[subscript]5Sb[subscript]3Fe in order to rationalize the ability of Zr[subscript]5Sb[subscript]3 to interstitially incorporate this remarkable array of chemically diverse elements. A high density of states at the Fermi energy, low lying and strongly bonding ZrSb states in the Zr[subscript]5Sb[subscript]3 host, and the strong bonding interactions between zirconium and the interstitial element, combine to permit the extensive interstitial chemistry observed;The zirconium-antimony binary system was reinvestigated in the course of the Zr[subscript]5Sb[subscript]3Z study. Five new phases were identified: Zr[subscript]5Sb[subscript]3 ( Y[subscript]5Bi[subscript]3-type), ZrSb[subscript]1-x (FeSi-type), ZrSb (ZrSb-type), ZrSb[subscript]2 ( PbCl[subscript]2-type), and Zr[subscript]2Sb[subscript]3. The structure type of an additional compound was elucidated, Zr[subscript]2Sb ( La[subscript]2Sb-type). The unique structure type for ZrSb was determined by a single crystal X-ray diffraction experiment, and structural refinements were also carried out for Zr[subscript]5Sb[subscript]3 ( Y[subscript]5Bi[subscript]3 and Mn[subscript]5Si[subscript]3) and ZrSb[subscript]2 ( PbCl[subscript]2).;Extended-Huckel band calculations were carried out on the two ZrSb[subscript]2 structural polymorphs, PbCl[subscript]2 and ZrSb[subscript]2 types. The results indicate a slight increase in Sb-Sb bonding and a decrease in Sb-Zr bonding in the ZrSb[subscript]2 structure compared with those in the PbCl[subscript]2 modification. The results also imply that there is only a limited amount of charge transfer in these compounds, and a Zintl phase description is inappropriate. ftn * DOE Report IS-T-1298. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy.

Subject Categories
Thu Jan 01 00:00:00 UTC 1987