Author: Bianzhu Fu
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 83
Book Description
Intrinsic thin film stress is evitable with the thin film deposition process and plays an important role in tuning the physical properties of thin films. In this thesis, the in situ and post growth stress evolution of the Fe-Pt and Fe-Cu alloy system was studied and correlated to the microstructure evolutions. At ambient temperature and constant deposition pressure, the growth stresses of both the Fe-Pt and Fe-Cu alloy were found to be dependent on the compositions and affected by their growth rates. The final intrinsic stress states after growth could be tuned to be either tensile, zero or compressive depending upon composition and deposition rate for similar grain sizes. This is due to the preferential segregation of one species (the more mobile element) to the grain boundaries. At elevated growth temperatures, the Fe-Pt alloy forms ordered phase while the Fe-Cu alloy forms phase separation. The magnitude of the compressive stress state is reduced as the Fe54Pt46 thin film orders in situ during growth. The compressive stress relaxation rate is increased with increasing substrate temperature or order parameter. This compressive stress reduction has been rationalized as a reduction of adatom mobility on the surface as Fe and Pt occupy specific lattice sites for L10 on each grain. The ordered nature of the grains contributes to additional chemical energy at the boundary which, upon ceasing deposition, significantly increases the stress relaxation rate. In contrary, the growth compressive stress of the Fe51Cu49 alloys in the continuous growth regime is increased with substrate temperature. This has been rationalized as the migration of adatoms to thermodynamically preferred surfaces during growth.
In Situ Growth Stresses in Iron-platinum and Iron-copper Alloy
Author: Bianzhu Fu
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 83
Book Description
Intrinsic thin film stress is evitable with the thin film deposition process and plays an important role in tuning the physical properties of thin films. In this thesis, the in situ and post growth stress evolution of the Fe-Pt and Fe-Cu alloy system was studied and correlated to the microstructure evolutions. At ambient temperature and constant deposition pressure, the growth stresses of both the Fe-Pt and Fe-Cu alloy were found to be dependent on the compositions and affected by their growth rates. The final intrinsic stress states after growth could be tuned to be either tensile, zero or compressive depending upon composition and deposition rate for similar grain sizes. This is due to the preferential segregation of one species (the more mobile element) to the grain boundaries. At elevated growth temperatures, the Fe-Pt alloy forms ordered phase while the Fe-Cu alloy forms phase separation. The magnitude of the compressive stress state is reduced as the Fe54Pt46 thin film orders in situ during growth. The compressive stress relaxation rate is increased with increasing substrate temperature or order parameter. This compressive stress reduction has been rationalized as a reduction of adatom mobility on the surface as Fe and Pt occupy specific lattice sites for L10 on each grain. The ordered nature of the grains contributes to additional chemical energy at the boundary which, upon ceasing deposition, significantly increases the stress relaxation rate. In contrary, the growth compressive stress of the Fe51Cu49 alloys in the continuous growth regime is increased with substrate temperature. This has been rationalized as the migration of adatoms to thermodynamically preferred surfaces during growth.
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 83
Book Description
Intrinsic thin film stress is evitable with the thin film deposition process and plays an important role in tuning the physical properties of thin films. In this thesis, the in situ and post growth stress evolution of the Fe-Pt and Fe-Cu alloy system was studied and correlated to the microstructure evolutions. At ambient temperature and constant deposition pressure, the growth stresses of both the Fe-Pt and Fe-Cu alloy were found to be dependent on the compositions and affected by their growth rates. The final intrinsic stress states after growth could be tuned to be either tensile, zero or compressive depending upon composition and deposition rate for similar grain sizes. This is due to the preferential segregation of one species (the more mobile element) to the grain boundaries. At elevated growth temperatures, the Fe-Pt alloy forms ordered phase while the Fe-Cu alloy forms phase separation. The magnitude of the compressive stress state is reduced as the Fe54Pt46 thin film orders in situ during growth. The compressive stress relaxation rate is increased with increasing substrate temperature or order parameter. This compressive stress reduction has been rationalized as a reduction of adatom mobility on the surface as Fe and Pt occupy specific lattice sites for L10 on each grain. The ordered nature of the grains contributes to additional chemical energy at the boundary which, upon ceasing deposition, significantly increases the stress relaxation rate. In contrary, the growth compressive stress of the Fe51Cu49 alloys in the continuous growth regime is increased with substrate temperature. This has been rationalized as the migration of adatoms to thermodynamically preferred surfaces during growth.
Metals Abstracts Index
Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1622
Book Description
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1622
Book Description
Thesaurus of Water Resources Terms
Author: United States. Bureau of Reclamation
Publisher:
ISBN:
Category : Hydraulic engineering
Languages : en
Pages : 356
Book Description
Publisher:
ISBN:
Category : Hydraulic engineering
Languages : en
Pages : 356
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704
Book Description
Metals Abstracts
Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1042
Book Description
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1042
Book Description
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 922
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 922
Book Description
American Doctoral Dissertations
Author:
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 532
Book Description
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 532
Book Description
List of Bureau of Mines Publications and Articles ... with Subject and Author Index
Author: United States. Bureau of Mines
Publisher:
ISBN:
Category : Mineral industries
Languages : en
Pages : 226
Book Description
Publisher:
ISBN:
Category : Mineral industries
Languages : en
Pages : 226
Book Description
Technical Abstract Bulletin
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1186
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1186
Book Description
The Journal of the Iron and Steel Institute
Author: Iron and Steel Institute
Publisher:
ISBN:
Category : Iron industry and trade
Languages : en
Pages : 592
Book Description
Includes the institute's Proceedings.
Publisher:
ISBN:
Category : Iron industry and trade
Languages : en
Pages : 592
Book Description
Includes the institute's Proceedings.