Making and Breaking Covalent Bonds across the Magnetic Transition in the Giant Magnetocaloric Material Gd{sub 5}(Si{sub 2}Ge{sub 2})

doi:10.1103/PhysRevLett.84.4617

Title: Making and Breaking Covalent Bonds across the Magnetic Transition in the Giant Magnetocaloric Material Gd{sub 5}(Si{sub 2}Ge{sub 2})

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Abstract

A temperature-dependent, single crystal x-ray diffraction study of the giant magnetocaloric material, Gd{sub 5}( Si{sub 2}Ge {sub 2}) , across its Curie temperature (276 K) reveals that the simultaneous orthorhombic to monoclinic transition occurs by a shear mechanism in which the (Si, Ge)- (Si, Ge) dimers that are richer in Ge increase their distances by 0.859(3) Angstrom and lead to twinning. The structural transition changes the electronic structure, and provides an atomic-level model for the change in magnetic behavior with temperature in the Gd{sub 5}( Si{sub x}Ge {sub 1-x}){sub 4} . (c) 2000 The American Physical Society.

Authors:

Choe, W. ^[1]; Pecharsky, V. K. ^[2]; Pecharsky, A. O. ^[2]; Gschneidner, K. A. Jr. ^[2]; Young, V. G. Jr. ^[3]; Miller, G. J. ^[1]

Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)
Ames Laboratory and Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011 (United States)
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

Publication Date:: 2000-05-15

OSTI Identifier:: 20216590

Resource Type:: Journal Article

Journal Name:: Physical Review Letters

Additional Journal Information:: Journal Volume: 84; Journal Issue: 20; Other Information: PBD: 15 May 2000; Journal ID: ISSN 0031-9007

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; 30 DIRECT ENERGY CONVERSION; GADOLINIUM ALLOYS; SILICON ALLOYS; GERMANIUM ALLOYS; X-RAY DIFFRACTION; MONOCRYSTALS; CHEMICAL BONDS; CURIE POINT; PHASE TRANSFORMATIONS; TWINNING; CRYSTAL STRUCTURE; ELECTRONIC STRUCTURE; TEMPERATURE DEPENDENCE; MAGNETO-THERMAL EFFECTS; EXPERIMENTAL DATA

Citation Formats


                    Choe, W., Pecharsky, V. K., Pecharsky, A. O., Gschneidner, K. A. Jr., Young, V. G. Jr., and Miller, G. J. Making and Breaking Covalent Bonds across the Magnetic Transition in the Giant Magnetocaloric Material Gd{sub 5}(Si{sub 2}Ge{sub 2}).  United States: N. p., 2000. 
        Web.  doi:10.1103/PhysRevLett.84.4617.

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                    Choe, W., Pecharsky, V. K., Pecharsky, A. O., Gschneidner, K. A. Jr., Young, V. G. Jr., & Miller, G. J. Making and Breaking Covalent Bonds across the Magnetic Transition in the Giant Magnetocaloric Material Gd{sub 5}(Si{sub 2}Ge{sub 2}).  United States.  doi:10.1103/PhysRevLett.84.4617.

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                    Choe, W., Pecharsky, V. K., Pecharsky, A. O., Gschneidner, K. A. Jr., Young, V. G. Jr., and Miller, G. J. Mon .  
        "Making and Breaking Covalent Bonds across the Magnetic Transition in the Giant Magnetocaloric Material Gd{sub 5}(Si{sub 2}Ge{sub 2})".  United States.  doi:10.1103/PhysRevLett.84.4617.

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@article{osti_20216590,

  title        = {Making and Breaking Covalent Bonds across the Magnetic Transition in the Giant Magnetocaloric Material Gd{sub 5}(Si{sub 2}Ge{sub 2})},

  author       = {Choe, W. and Pecharsky, V. K. and Pecharsky, A. O. and Gschneidner, K. A. Jr. and Young, V. G. Jr. and Miller, G. J.},

  abstractNote = {A temperature-dependent, single crystal x-ray diffraction study of the giant magnetocaloric material, Gd{sub 5}( Si{sub 2}Ge {sub 2}) , across its Curie temperature (276 K) reveals that the simultaneous orthorhombic to monoclinic transition occurs by a shear mechanism in which the (Si, Ge)- (Si, Ge) dimers that are richer in Ge increase their distances by 0.859(3) Angstrom and lead to twinning. The structural transition changes the electronic structure, and provides an atomic-level model for the change in magnetic behavior with temperature in the Gd{sub 5}( Si{sub x}Ge {sub 1-x}){sub 4} . (c) 2000 The American Physical Society.},

  doi          = {10.1103/PhysRevLett.84.4617},

  journal      = {Physical Review Letters},

  issn         = {0031-9007},

  number       = 20,

  volume       = 84,

  place        = {United States},

  year         = {2000},

  month        = {5}

}

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DOI: 10.1103/PhysRevLett.84.4617

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