Search results for "properties"

Design Scheme of New Tetragonal Heusler Compounds for Spin-Transfer Torque Applications and its Experimental Realization

2012

Band Jahn-Teller type structural instabilities of cubic Mn(2)YZ Heusler compounds causing tetragonal distortions can be predicted by ab initio band-structure calculations. This allows for identification of new Heusler materials with tunable magnetic and structural properties that can satisfy the demands for spintronic applications, such as in spin-transfer torque-based devices.

Statistical analysis of the relation between metallic microstructures and mechanical properties

2020

This thesis aims at the development of physical relations between the intricate 3D features of metallic microstructures and the mechanical properties of the material. For understanding which are the microstructural determinants of the resultingmechanical behaviour of metals, a deep quantitative characterisation of the microstructure is needed. The main steps of quantitative characterisation of the microstructures are: identification of the phases distribution and their chemical composition, study of the microstructure morphology (geometrical arrangement of grains, grain boundaries, grain orientations, grain size and grain shape). An accurate description of the microstructure features enrich…

Spin Crossover and Long-Lived Excited States in a Reduced Molecular Ruby.

2020

Abstract The chromium(III) complex [CrIII(ddpd)2]3+ (molecular ruby; ddpd=N,N′‐dimethyl‐N,N′‐dipyridine‐2‐yl‐pyridine‐2,6‐diamine) is reduced to the genuine chromium(II) complex [CrII(ddpd)2]2+ with d4 electron configuration. This reduced molecular ruby represents one of the very few chromium(II) complexes showing spin crossover (SCO). The reversible SCO is gradual with T 1/2 around room temperature. The low‐spin and high‐spin chromium(II) isomers exhibit distinct spectroscopic and structural properties (UV/Vis/NIR, IR, EPR spectroscopies, single‐crystal XRD). Excitation of [CrII(ddpd)2]2+ with UV light at 20 and 290 K generates electronically excited states with microsecond lifetimes. This…

Investigating the Structural Properties of an IT-Enabled Resource

2019

The synergistic combination and integration of information technology (IT) and other complementary organizational resources to form IT-enabled resources, has long been identified as one means through which organizations can derive benefits from IT. However, research shows that the integration required to form IT-enabled resources from which organizations derive benefits, also constrains the renewal and redeployment of the IT-enabled resources to address new strategic imperatives. Thus, there are several calls for further research on how organizations can sustain the derivation of benefits from IT especially in dynamic environments. This study responds to such calls. Specifically, it draws o…

Flat-band superconductivity in strained Dirac materials

2016

We consider superconducting properties of a two-dimensional Dirac material such as graphene under strain that produces a flat band spectrum in the normal state. We show that in the superconducting state, such a model results in a highly increased critical temperature compared to the case without the strain, inhomogenous order parameter with two-peak shaped local density of states and yet a large and almost uniform and isotropic supercurrent. This model could be realized in strained graphene or ultracold atom systems and could be responsible for unusually strong superconductivity observed in some graphite interfaces and certain IV-VI semiconductor heterostructures.

Theoretical investigation of the electronic structure of fullerenes

1994

Summary form only given. Research in the growing family of fullerene compounds are in continuous expansion. Much theoretical and experimental effort has been devoted to the study of the electronic properties these carbon cages present. However, although significant work has been done, the purpose of this paper is to provide a detailed theoretical analysis of the electronic properties of several fullerenes. We have calculated the electronic structure of these carbon cages within the valence effective Hamiltonian (VEH) approach. The calculated one-electron energy levels are correlated with experimental UPS spectra. The good correlation between calculated and experimental values shows VEH appr…

1973

The direct and the inverse problem of the light scattering from dilute polymer solutions is solved for GAUssian coils at the theta point. Theoretical scattering functions and their derivatives are analytically calculated for the general gamma distribution of molecular weights as a function of the non-uniformity and the weight average molecular weight, and also for various ratios of the statistical segment length of the coil to the wave length of the scattered light. The asymptote and the tangent of P are obtained by analysing the operator in the ZIMM equation and their mutual position is compared in the angle range 150° to 180°. The scattering envelopes of microgel systems are analytically …

Formulas for the thermodynamic properties of dense nitrogen.

1969

Poliolefiny a środowisko

2002

Przedstawiono znaczenie, rozwój metod otrzymywania, kierunki zastosowania i perspektywy rozwoju poliolefin (polietylenu i polipropylenu), materiałów dominujących w światowej produkcji i zużyciu tworzyw sztucznych. Scharakteryzowano oddziaływania tych polimerów na środowisko, kolejno w etapie ich wytwarzania, wykorzystywania i utylizacji odpadów poużytkowych. Scharakteryzowano także kierunki badań prowadzonych w Instytucie Chemii Uniwersytetu Opolskiego w zakresie syntezy, charakterystyki, a przede wszystkim temo- i fotooksydacyjnej degradacji oraz starzenia atmosferycznego poliolefin.

Adsorption and Activation of Water on Cuboctahedral Rhodium and Platinum Nanoparticles

2017

Rh and Pt are widely used as the components in heterogeneous catalysts for multiple industrial applications. Because the metals are typically in the form of nanoparticles in real catalysts, it is important to carefully select models for the computational prediction of the catalytic properties. Here we report a first-principles study on the water activation, an important step in numerous catalytic reactions, using the finite-size Rh and Pt nanoparticle models and compare them to the extended surface models. We show that regardless of the model, adsorption and activation of water is practically identical for both metals, whereas the dissociation is energetically more favorable on Rh. The expe…