Samuel Castro Lucas
M.S. FinalMar 19, 2024, 2:00 pm - 3:15 pm
ERC electronic classroom A210
INVESTIGATION ON THE STRUCTURAL, MECHANICAL AND OPTICAL PROPERTIES OF AMORPHOUS OXIDE THIN FILMS FOR GRAVITATIONAL WAVE DETECTORS.
Abstract: Amorphous metallic oxide thin films, grown through physical vapor deposition methods like ion beam sputtering, play a crucial role in optical interference coatings for high finesse optical cavities, such as those used in gravitational wave detectors. The stability of these atomically disordered solids, existing in a non-equilibrium metastable state, is significantly influenced by both deposition conditions and composition. Consequently, this enables the tuning of structural, mechanical, or optical properties.
Moreover, current noise contributions impede the detection of even minor strain signals from gravitational waves. One of the primary thermal noises is associated with thermally driven random displacement fluctuations, known as Brownian motion, within the suspended mirror amorphous optical coatings. This motion entails a damping effect as internal friction, acting as an anelastic relaxation mechanism by dissipating energy following each oscillation cycle. The quantification of internal friction can be achieved through the mechanical loss angle (Q-1). Furthermore, structural relaxations via post-deposition annealing are employed to mitigate mechanical loss. Nonetheless, comprehending the structural, mechanical, and optical alterations following annealing is critical in identifying both macroscopic and microscopic behaviors for low thermal noise materials, as well as for practical implementation.
The first study examines the structural interaction between two distinct amorphous oxides following post-annealing, specifically TiO2 with GeO2 and SiO2.
The second study investigates the structural, mechanical, and optical properties of amorphous ternary oxide mixtures following post-annealing. These mixtures consist of TiO2:GeO2 combined with SiO2 and ZrO2, as well as TiO2:SiO2 combined with ZrO2.
Moreover, current noise contributions impede the detection of even minor strain signals from gravitational waves. One of the primary thermal noises is associated with thermally driven random displacement fluctuations, known as Brownian motion, within the suspended mirror amorphous optical coatings. This motion entails a damping effect as internal friction, acting as an anelastic relaxation mechanism by dissipating energy following each oscillation cycle. The quantification of internal friction can be achieved through the mechanical loss angle (Q-1). Furthermore, structural relaxations via post-deposition annealing are employed to mitigate mechanical loss. Nonetheless, comprehending the structural, mechanical, and optical alterations following annealing is critical in identifying both macroscopic and microscopic behaviors for low thermal noise materials, as well as for practical implementation.
The first study examines the structural interaction between two distinct amorphous oxides following post-annealing, specifically TiO2 with GeO2 and SiO2.
The second study investigates the structural, mechanical, and optical properties of amorphous ternary oxide mixtures following post-annealing. These mixtures consist of TiO2:GeO2 combined with SiO2 and ZrO2, as well as TiO2:SiO2 combined with ZrO2.
Adviser: Carmen Menoni
Co-Adviser: NA
Non-ECE Member: Justin Sambur
Member 3: Jorge Rocca
Addional Members: NA
Co-Adviser: NA
Non-ECE Member: Justin Sambur
Member 3: Jorge Rocca
Addional Members: NA
Publications:
NA
NA
Program of Study:
ECE 574
ECE 506
ECE 673
ECE 471A
ECE 441
ECE 404
CHEM 550A
MECH 544
ECE 574
ECE 506
ECE 673
ECE 471A
ECE 441
ECE 404
CHEM 550A
MECH 544