Microstructure study of the rare-earth intermetallic compounds R₅(Si_xGe_1-x)₄ and R₅(Si_xGe_1-x)₃

Thesis/Dissertation · Sun Jan 01 00:00:00 EST 2012

DOI:https://doi.org/10.2172/1048540· OSTI ID:1048540

Cao, Qing ^[1]

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1. Iowa State Univ., Ames, IA (United States)

The unique combination of magnetic properties and structural transitions exhibited by many members of the R₅(Si_xGe_1-x)₄ family (R = rare earths, 0 ≤ x ≤ 1) presents numerous opportunities for these materials in advanced energy transformation applications. Past research has proven that the crystal structure and magnetic ordering of the R₅(Si_xGe_1-x)₄ compounds can be altered by temperature, magnetic field, pressure and the Si/Ge ratio. Results of this thesis study on the crystal structure of the Er₅Si₄ compound have for the first time shown that the application of mechanical forces (i.e. shear stress introduced during the mechanical grinding) can also result in a structural transition from Gd₅Si₄-type orthorhombic to Gd₅Si₂Ge₂-type monoclinic. This structural transition is reversible, moving in the opposite direction when the material is subjected to low-temperature annealing at 500 °C.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC02-07CH11358
• OSTI ID: 1048540
• Report Number(s): IS-T 3072
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE