STRUCTURAL, MAGNETIC AND ELECTRICAL PROPERTIES OF Ho AND Ni CO-DOPED BiFeO3 MATERIALS

Pure BiFeO3 (BFO) and Bi1-xHoxFe0.97Ni0.03O3 (x = 0.00, 0.025, 0.05, 0.075, and 0.10) materials were synthesised by sol-gel method. Effects of (Ho, Ni) co-doping on structural, magnetic and electrical properties of BFO materials were investigated by different techniques as X-ray diffraction (XRD), energy dispersion X-ray (EDX), Raman scattering, magnetic hysteresis (M-H) loops, and complex impedance spectra measurement. Analysis results of XRD measurement shows that all samples crystallize in the rhombohedral structure with R3C space group. BFO in the rhombohedral structure has crystal lattice parameters a = 5.584 Å, c = 13.867 Å and average crystal size LXRD = 60 nm. The x = 0.00 sample (BFNO) has a = 5.589 Å, c = 13.875 Å and LXRD = 60 nm. However, the crystal lattice parameters a, c and average crystal size LXRD of (Ho, Ni) co-doped samples decrease when concentration of Ho increases. Results of Raman scattering spectra shows that the peaks position characteristic for Fe-O bonds of x = 0.00 sample shifts toward lower frequency compare to that of BFO. For the (Ho, Ni) co-doped samples (BHFNO), the peaks position characteristic for Bi-O convalent bonds shifts toward higher frequency when concentration of Ho increases. Which confirmed that Ho3+ and Ni2+ ions substituted into Bi-sites and Fe-sites, respectively. From data of magnetic hysteresis loops measurement indicates that all samples present weak ferromagnetic. BFO sample presents weak ferromagnetic properties with saturation magnetization Ms = 0.047 emu/g and remnant magnetization Mr = 0.008 emu/g. Ferromagnetic properties of (Ho, Ni) co-doped samples enhance compare to that of BFO. In this report, we will discuss the origin of ferromagnetism of materials

The Battle for Dominance: Innovating Firms\u27 Strategic Market Success in the Context of a Standards War

To increase the likelihood of success of their market-focused innovations, firms that develop innovations for targeted markets regularly communicate with market participants in order to reduce the uncertainties participants hold regarding the firms’ innovations. Among other tactics, these firms employ strategic market signals. The paper develops three types of uncertainty (technical, market and standards) associated with the market-focused innovations as well as hypotheses related to the impacts of firms’ signals, which are used to address the uncertainty issues, on firms’ market success during the standards war. The research findings have implications for both theory and practice

Spin-chirality decoupling in the one-dimensional Heisenberg spin glass with long-range power-law interactions

We study the issue of the spin-chirality decoupling/coupling in the ordering of the Heisenberg spin glass by performing large-scale Monte Carlo simulations on a one-dimensional Heisenberg spin-glass model with a long-range power-law interaction up to large system sizes. We find that the spin-chirality decoupling occurs for an intermediate range of the power-law exponent. Implications to the corresponding $d$-dimensional short-range model is discussed.Comment: 5 pages, 4 figures, to appear in Physical Review Letter

Piezoresistive effect of p-type single crystalline 3C-SiC on (111) plane

This paper presents for the first time the effect of strain on the electrical conductivity of p-type single crystalline 3C-SiC grown on a Si (111) substrate. 3C-SiC thin film was epitaxially formed on a Si (111) substrate using the low pressure chemical vapor deposition process. The piezoresistive effect of the grown film was investigated using the bending beam method. The average longitudinal gauge factor of the p-type single crystalline 3C-SiC was found to be around 11 and isotropic in the (111) plane. This gauge factor is 3 times smaller than that in a p-type 3C-SiC (100) plane. This reduction of the gauge factor was attributed to the high density of defects in the grown 3C-SiC (111) film. Nevertheless, the gauge factor of the p-type 3C-SiC (111) film is still approximately 5 times higher than that in most metals, indicating its potential for niche mechanical sensing applications

Monte Carlo studies of the chiral and spin orderings of the three-dimensional Heisenberg spin glass

The nature of the ordering of the three-dimensional isotropic Heisenberg spin glass with nearest-neighbor random Gaussian coupling is studied by extensive Monte Carlo simulations. Several independent physical quantities are measured both for the spin and for the chirality, including the correlation-length ratio, the Binder ratio, the glass order parameter, the overlap distribution function and the non-self-averageness parameter. By controlling the effect of the correction-to-scaling, we have obtained a numerical evidence for the occurrence of successive chiral-glass and spin-glass transitions at nonzero temperatures, T_{CG} > T_{SG} > 0. Hence, the spin and the chirality are decoupled in the ordering of the model. The chiral-glass exponents are estimated to be \nu_{CG}=1.4+-0.2 and \eta_{CG}=0.6+-0.2, indicating that the chiral-glass transition lies in a universality class different from that of the Ising spin glass. The possibility that the spin and chiral sectors undergo a simultaneous Kosterlitz-Thouless-type transition is ruled out. The chiral-glass state turns out to be non-self-averaging, possibly accompanying a one-step-like peculiar replica-symmetry breaking. Implications to the chirality scenario of experimental spin-glass transitions are discussed.Comment: 20 pages, 24 figures. The Chi^2-analysis of the transition point has been added with new Fig.12. Some references also adde

An Empirical Examination of the Use of IS-enabled Sustainability Initiatives Across the Integrated Sustainability Framework

Background: Using the Resource Based View (RBV) and the Integrated Sustainability Framework (ISF) as theoretical foundation, this study proposes and empirically examines hypotheses on how different types of IS-enabled sustainability initiatives are used to enable environmental and social sustainability in the four quadrants of the ISF. Method: The study uses a mixed-method approach, combining multiple-case study and non-parametric statistical analysis (Friedman test). IS-enabled sustainability initiatives were collected from Global Reporting Initiative (GRI) reports of six leading global sustainability companies across three industries with different levels of IS/IT use intensity during 2009-2015 period. Results: The study finds empirical quantitative and qualitative support for the proposed hypotheses. In different quadrants of the ISF, companies were found to use different types of IS-enabled sustainability initiatives in different patterns to enable sustainability strategy. Conclusions: The study opens the IS box to provide further theoretical and empirical insights on how companies combine IS and business resources to develop different types of IS-enabled sustainability initiatives to help them address sustainability (both environmental and social) across the ISF. The study is among early IS research that adopts GRI reports as data source and presents a method for extracting GRI data for IS and sustainability research. Researchers and practitioners can both find the study’s findings instructive