A5029559380- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Atomic and Subatomic Physics Research
- Ferroelectric and Piezoelectric Materials
- Magnetic properties of thin films
- Advanced NMR Techniques and Applications
- Multiferroics and related materials
- Magnetic Properties and Synthesis of Ferrites
- Nuclear Physics and Applications
- Characterization and Applications of Magnetic Nanoparticles
- Superconductivity in MgB2 and Alloys
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Solid-state spectroscopy and crystallography
- Organic Electronics and Photovoltaics
- Quantum, superfluid, helium dynamics
- Various Chemistry Research Topics
- High-pressure geophysics and materials
- Magnetic Properties of Alloys
- Silicon and Solar Cell Technologies
- Advanced MRI Techniques and Applications
- Minerals Flotation and Separation Techniques
- Microwave Dielectric Ceramics Synthesis
- Force Microscopy Techniques and Applications
- Magnetic Properties and Applications
The University of Texas at Austin
2009-2015
Whether in medical or security applications, magnetic resonance spectroscopy is very useful for detecting faint signals from target compounds. However, interference (from $e.g.$ a local radio station) can be problem. The authors devise optical atomic-gas detectors that work unshielded environments, and without cryogenic cooling---important advantages real-world use. These sensitive, compact systems offer baseline noise at the quantum limit.
Magnetic force microscopy was performed on 300 nm thick magnetite films grown epitaxially MgO (001) at temperatures ranging from well below to above the Verwey transition temperature, TV. Frequency shift images were acquired different locations sample as temperature increased through transition. The magnetic domain features are persistent all temperatures, which indicates that domains pinned across phase transition, probably due antiphase boundaries. An enhancement of contrast TV moments...
3000 Å Fe3O4 (magnetite) thin films were simultaneously grown on (001) MgO single crystal substrates with and without 30 buffer layers of Fe, Cr, Mo, Nb. For all samples, the Verwey transition temperature (TV) occurs between 119 125 K, indicating good oxygen stoichiometry. We observe highly oriented Mo no layer, reduced texture Nb polycrystalline growth Cr. unbuffered magnetite show typical magnetic behavior, whereas Fe buffers lead to anomalous properties that may be due interfacial reactivity.
Nuclear Quadrupole Resonance (NQR) is a highly selective spectroscopic method that can be used to detect and identify number of chemicals interest the defense, national security, law enforcement community. In past, there have been several documented attempts utilize NQR nitrogen bearing explosives using induction sensors RF signatures. We present here our work on detection explosive simulants optically pumped atomic magnetometers. magnetometers provide an order magnitude (or more)...
Nuclear Quadrupole Resonance (NQR) has been demonstrated for the detection of 14-N in explosive compounds. Application a material specific radio-frequency (RF) pulse excites response typically detected with wire- wound antenna. NQR is non-contact and specific, however fields produced by are very weak, making demonstration practical utility challenging. For certain materials, signal can be increased transferring polarization from hydrogen nuclei to nitrogen using external magnetic fields....
We report imaging and dynamical measurements using a H3e nuclear magnetic resonance force microscopy probe. Relaxation-time one-dimensional image were obtained for H1 nuclei in micron-scale crystal of (NH4)2SO4. The detection was made possible by small Permalloy magnet, which supplied field gradient 500 T/m. These experiments performed the sample-on-oscillator configuration at room temperature, where oscillator had frequency 1.5 kHz spring constant 0.03 N/m. proton moments underwent cyclic...
This work reports efforts fabricating heterostructures of different materials relevant for the realization magnon-induced spin transfer torques. We find growth high-quality magnetite on MgO substrates to be straightforward, while using transition metal buffer layers Fe, Cr, Mo, and Nb can alter structural magnetic properties magnetite. Additionally, we successfully fabricated characterized Py/Cr/Fe 3 O 4 Fe /Cr/Fe valve structures. For both, observe a relatively small giant magnetoresistance...