National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.

Details

Critical Behavior of Thermal Expansion and Magnetostriction in the Vicinity of the First Order Transition at the Curie Point of Gd5(SiXGe1-x)4.

DE2005837267

Publication Date	2004
Personal Author	Han, M.
Page Count	188
Abstract	Thermal expansion (TE) and magnetostriction (MS) measurements have been conducted for Gd(sub 5)(Si(sub x)Ge(sub 1-x))(sub 4) with a series of x values to study its critical behavior in the vicinity of transition temperatures. It was found that the Curie temperature of Gd(sub 5)(Si(sub x)Ge(sub 1-x))(sub 4) for x 0 (approx.) 0.5 is dependent on magnetic field, direction of change of temperature (Tc on cooling was lower than Tc on heating), purity of Gd starting material, compositions, material preparation methods, and also can be triggered by the external magnetic field with a different dT/dB rate for different x values. For Gd(sub 5)(Si(sub 1.95)Ge(sub 2.05)), Gd(sub 5)(Si(sub 2)Ge(sub 2)), Gd(sub 5)(Si(sub 2.09)Ge(sub 1.91)), it was also found that the transition is a first order magneto-structural transition, which means the magnetic transition and crystalline structure transition occur simultaneously, and completely reversible. Temperature hysteresis and phase coexistence have been found to confirm that it is a first order transformation. While for Gd(sub 5)(Si(sub 0.15)Ge(sub 3.85)), it is partially reversible at some temperature range between the antiferromagnetic and the ferromagnetic state.
Keywords	Curie point Thermal expansion Magnetostriction Heating Hysteresis Magnetic fields Monocrystals Polycrsytals Strains Transformations Transition temperature
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Iowa State Univ., Ames.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200601

Critical Behavior of Thermal Expansion and Magnetostriction in the Vicinity of the First Order Transition at the Curie Point of Gd5(SiXGe1-x)4.

Critical Behavior of Thermal Expansion and Magnetostriction in the Vicinity of the First Order Transition at the Curie Point of Gd5(SiXGe1-x)4.
DE2005837267

Publication Date	2004
Personal Author	Han, M.
Page Count	188
Abstract	Thermal expansion (TE) and magnetostriction (MS) measurements have been conducted for Gd(sub 5)(Si(sub x)Ge(sub 1-x))(sub 4) with a series of x values to study its critical behavior in the vicinity of transition temperatures. It was found that the Curie temperature of Gd(sub 5)(Si(sub x)Ge(sub 1-x))(sub 4) for x 0 (approx.) 0.5 is dependent on magnetic field, direction of change of temperature (Tc on cooling was lower than Tc on heating), purity of Gd starting material, compositions, material preparation methods, and also can be triggered by the external magnetic field with a different dT/dB rate for different x values. For Gd(sub 5)(Si(sub 1.95)Ge(sub 2.05)), Gd(sub 5)(Si(sub 2)Ge(sub 2)), Gd(sub 5)(Si(sub 2.09)Ge(sub 1.91)), it was also found that the transition is a first order magneto-structural transition, which means the magnetic transition and crystalline structure transition occur simultaneously, and completely reversible. Temperature hysteresis and phase coexistence have been found to confirm that it is a first order transformation. While for Gd(sub 5)(Si(sub 0.15)Ge(sub 3.85)), it is partially reversible at some temperature range between the antiferromagnetic and the ferromagnetic state.
Keywords	Curie point Thermal expansion Magnetostriction Heating Hysteresis Magnetic fields Monocrystals Polycrsytals Strains Transformations Transition temperature
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Iowa State Univ., Ames.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200601