|
|
Design of mobile vacuum chamber for loading samples into high-frequency electron paramagnetic resonance spectrometer
Láznička, Tomáš ; Slageren, Joris van (oponent) ; Neugebauer, Petr (vedoucí práce)
In order to be able to characterize atmosphere sensitive samples in high-frequency electron paramagnetic resonance spectrometer (HF-EPR), a system of vacuum transportation is needed. The scope of this thesis is to design and develop a vacuum transport system which will allow this transportation. The vacuum system, which consists of a mobile vacuum suitcase, palette holder and airlock, was designed, assembled and tested. The pressure of 4.3 10^{-10} mbar was achieved, which will ensure inert condition for sample transportation. The transport of the sample from an ultra-high vacuum (UHV) cluster to the HF-EPR spectrometer was performed. The contamination of the test samples was characterized using x-ray photoelectron spectroscopy. It was found that there is no detectable contamination if the sample is in the vacuum system for less than 16 hours. The extension for transportation of the samples from a glove box and sample palette for graphene were proposed, but their production has not been performed yet. The developed vacuum system is fully functional and provides the alternative to commercially available products, thus it will be further used in the investigation of an atmosphere sensitive samples in CEITEC Nano laboratories.
|
|
|
Development of a Novel Terahertz Magnetic Resonance Spectrometer for Spin Dynamics Investigations
Sojka, Antonín ; Smith, Graham Murray (oponent) ; Tseytlin, Mark (oponent) ; Neugebauer, Petr (vedoucí práce)
During the last decades, the method called High Frequency/Field Electron Paramagnetic Resonance (HF-EPR) spectroscopy experienced a boom in chemistry, biology, material science, and physics. Still, HF-EPR spectrometers operating at sub-THz frequencies are mostly custom-made with non-standard solutions. The thesis aims to develop a novel broadband EPR spectrometer capable of operating in the field and frequency domain and performing frequency domain rapid scan to study relaxation times. The spectrometer operates at high magnetic fields up to 16\,T, broad frequency range from 90 to 1100 GHz, and temperature ranges of 4 –- 400\,K. Furthermore, The work describes the design and development of six different exchangeable sample holders with a proof-of functionality measurement and unique fast-loading flange for the sample holder. The capability of the spectrometer to perform Rapid Scan measurement is demonstrated in the measurements of the LiPc single crystal and the DPPH sample dissolved in toluene.
|
|
|
Development of a Novel Terahertz Magnetic Resonance Spectrometer for Spin Dynamics Investigations
Sojka, Antonín ; Smith, Graham Murray (oponent) ; Tseytlin, Mark (oponent) ; Neugebauer, Petr (vedoucí práce)
During the last decades, the method called High Frequency/Field Electron Paramagnetic Resonance (HF-EPR) spectroscopy experienced a boom in chemistry, biology, material science, and physics. Still, HF-EPR spectrometers operating at sub-THz frequencies are mostly custom-made with non-standard solutions. The thesis aims to develop a novel broadband EPR spectrometer capable of operating in the field and frequency domain and performing frequency domain rapid scan to study relaxation times. The spectrometer operates at high magnetic fields up to 16\,T, broad frequency range from 90 to 1100 GHz, and temperature ranges of 4 –- 400\,K. Furthermore, The work describes the design and development of six different exchangeable sample holders with a proof-of functionality measurement and unique fast-loading flange for the sample holder. The capability of the spectrometer to perform Rapid Scan measurement is demonstrated in the measurements of the LiPc single crystal and the DPPH sample dissolved in toluene.
|
|
|
Design of mobile vacuum chamber for loading samples into high-frequency electron paramagnetic resonance spectrometer
Láznička, Tomáš ; Slageren, Joris van (oponent) ; Neugebauer, Petr (vedoucí práce)
In order to be able to characterize atmosphere sensitive samples in high-frequency electron paramagnetic resonance spectrometer (HF-EPR), a system of vacuum transportation is needed. The scope of this thesis is to design and develop a vacuum transport system which will allow this transportation. The vacuum system, which consists of a mobile vacuum suitcase, palette holder and airlock, was designed, assembled and tested. The pressure of 4.3 10^{-10} mbar was achieved, which will ensure inert condition for sample transportation. The transport of the sample from an ultra-high vacuum (UHV) cluster to the HF-EPR spectrometer was performed. The contamination of the test samples was characterized using x-ray photoelectron spectroscopy. It was found that there is no detectable contamination if the sample is in the vacuum system for less than 16 hours. The extension for transportation of the samples from a glove box and sample palette for graphene were proposed, but their production has not been performed yet. The developed vacuum system is fully functional and provides the alternative to commercially available products, thus it will be further used in the investigation of an atmosphere sensitive samples in CEITEC Nano laboratories.
|
host ::
RSS.