A5069594430- Theoretical and Computational Physics
- High-pressure geophysics and materials
- Advanced NMR Techniques and Applications
- Metallic Glasses and Amorphous Alloys
- Diamond and Carbon-based Materials Research
- Material Dynamics and Properties
- Silicon Nanostructures and Photoluminescence
- Electron Spin Resonance Studies
- Magnetism in coordination complexes
- Glass properties and applications
- Graphene research and applications
- Iron-based superconductors research
- Superconductivity in MgB2 and Alloys
- Physics of Superconductivity and Magnetism
- Catalytic Processes in Materials Science
- Nanoporous metals and alloys
- Magnetic properties of thin films
- Boron and Carbon Nanomaterials Research
- Muon and positron interactions and applications
- Advanced Chemical Physics Studies
- Semiconductor materials and interfaces
- Carbon Nanotubes in Composites
- Semiconductor materials and devices
- Phase-change materials and chalcogenides
- Surfactants and Colloidal Systems
Universidad Nacional Autónoma de México
2012-2024
University of Oxford
1993-2001
To investigate the relationship between atomic topology, vibrational and electronic properties superconductivity of bismuth, a 216-atom amorphous structure (a-Bi216) was computer-generated using our undermelt-quench approach. Its pair distribution function compares well with experiment. The calculated densities states (eDOS vDOS, respectively) show that eDOS is about 4 times crystalline at Fermi energy, whereas for vDOS energy range roughly same as but shapes are quite different. A simple...
We use zero- and longitudinal-field muon spin rotation relaxation to study the states in organic molecular ferromagnet: β-phase para-nitrophenyl nitronyl nitroxide (p-NPNN). Below TC = 0.65 K, oscillations function are observed zero applied field which follow magnetic order parameter, implying that is bonded an electronic spin-singlet state. also behaviour of longitudinal interpret results by considering magnetisation process demagnetising field. A significant field-induced repolarisation...
A thermal procedure and an ab initio molecular-dynamics method based on the Harris functional, applied to originally crystalline, periodically continued 64-atom cubic cells, is used generate random networks of four different materials varying degrees covalency: C, Si, Ge, a nearly stoichiometric sample Si-N. We obtain their radial distribution functions (RDF's) for time steps, one each material, using densities dictated by experiment. The simulated RDF's amorphous Ge show characteristic...
Abstract Boron Nitride (BN) is an interesting polymorphic insulator that commonly found in four different crystalline structures, each one with electrical and mechanical properties which makes it attractive material for technological industrial applications. Seeking to improve its features, several experimental simulational works have studied the amorphous phase (a-BN) focusing on electronic structural properties, pressure-induced transformations, a hydrogenated form of a-BN. By means ab...
The first successful theory of superconductivity was the one proposed by Bardeen, Cooper and Schrieffer in 1957. This breakthrough fostered a remarkable growth field that propitiated progress questionings, generating alternative theories to explain specific phenomena. For example, it has been argued Bismuth, being semimetal with low number carriers, does not comply basic hypotheses underlying BCS therefore different approach should be considered. Nevertheless, 2016 based on we put forth...
Magnetism in palladium has been the subject of much work and speculation. Bulk crystalline is paramagnetic with a high magnetic susceptibility. Palladium under pressure nanoclusters have generated interest to scrutinize its properties. Here we report another possibility: may become an itinerant ferromagnet amorphous bulk phase at atmospheric pressure. Atomic d$^{10}$ element, whereas Pd d$^{10-x}$(sp)$^{x}$ material; this, together possible presence 'unsaturated bonds' materials, explain...
Abstract All solid phases of bismuth under pressure, but one, have been experimentally found to superconduct. From Bi-I Bi-V, avoiding Bi-IV, they become superconductors and perhaps Bi-IV may also superconductive. To investigate the influence electronic properties N(E ) vibrational F(ω) on their superconductivity we ab initio calculated them for corresponding experimental crystalline structures, using a BCS approach able determine critical temperatures T c obtaining results close experiment:...
We report the results of muon-spin-rotation/relaxation () experiments on two recently discovered nitronyl nitroxides, 1- and 2-naphthyl nitroxide (1-NAPNN 2-NAPNN). These compounds are chemical isomers but, because their slightly different molecular shapes, they have quite crystal packing. A clear magnetic transition in zero-field muon-spin relaxation is observed 1-NAPNN below 100 mK while no such seen 2-NAPNN. support postulate that structure strongly influences nature ground states these materials.
We report the results of a study metal-organic magnets MII[N(CN)2]2, where MII = Ni, Co and Mn, using bulk magnetization muon-spin relaxation (µSR). Implanted muons are sensitive to onset long-range magnetic order in each these materials strong is observed paramagnetic state due low-frequency fluctuations electronic moments 109-1010 Hz range. The size can be related magnitude transition-metal-ion moment. Very strongly damped oscillations below transition temperature Co[N(CN)2]2.