Invar Behavior and Martensitic Transitions in FeNiPt Alloys

We determined the structural and the magnetic phase diagram for the disordered, ternary system FeNiPt in the Fe-rich corner in the vicinity of the γ(fcc)-α(bbc) transition region along the quasi binary cross section Fe1-x(Pt50Ni50)x with x=0.28, 0.3, 0.31, 0.32 and 0.35. All alloys are characterized by X-ray investigations, magnetization measurements M(T,H) (4.2≤T≤850K), as well as resistivity R(T) and thermal expansion measurements α(T) below 300K. We observe for x≤0.31 a non reversible, γ-α martensitic phase transition. In the alloys with x> 0.31 the γ(fcc) phase is stable down to 4.2K, and pronounced magneto-volume effects (Invar-like behavior) is observed. For the alloys close to the γ-α transition, the magnetic behavior M(T,H) is also discussed

MAGNETOSTRICTION IN FERRO- AND ANTIFERROMAGNETIC Fe-Ni-Mn ALLOYS

We have investigated the magnetostriction parallel to an external field of ferro- and antiferromagnetic alloys in the fcc Invar system Fe50NixMn50 - x using samples with x = 23.8, 26.5, 34.8 and 36.5 at.% . Results show unique behavior which reflect the properties of magnetically ordered and disordered states

MAGNETIZATION AND THERMAL EXPANSION IN Fe-Mn AND Fe-Mn-C ALLOYS

We have investigated the thermal expansion, α(T), and the magnetic susceptibility, χ(T), of antiferromagnetic Invar-type Fe100-xMnx and (Fe0.7Mn0.3)100-x Cx. Evidence for the existence of a spin-glass-like phase and ferromagnetic inhomogeneities is suggested by the χ(T) data. α(T) shows an anomaly which becomes less pronounced with the addition of C

Carbon nanotube bolometer: Transport properties and noise characteristics

The temperature dependent resistance and the noise characteristics of an individual multiwall carbon nanotube (CNT) decorated with a finite number of magnetic nanocubes are investigated. We show that CNT is a highly sensitive bolometer and can enable measurements of magnetic resonance in a single nanoparticle. © (2012) Trans Tech Publications

Carbon nanotube bolometer: Transport properties and noise characteristics

The temperature dependent resistance and the noise characteristics of an individual multiwall carbon nanotube (CNT) decorated with a finite number of magnetic nanocubes are investigated. We show that CNT is a highly sensitive bolometer and can enable measurements of magnetic resonance in a single nanoparticle. © (2012) Trans Tech Publications

Effect of microwave irradiation on spin-torque-driven magnetization precession in nanopillars with magnetic perpendicular anisotropy

International audienceThe effect of microwave irradiation on the spin-torque-driven magnetization dynamics is studied in (Co/Ni)-based nanopillar spin valves with perpendicular magnetic anisotropy. For this purpose, a setup was developed to measure the ac as well as the dc resistance of the nanopillar under applied fields and injected polarized currents, while irradiating microwaves with varying frequency (6-18 GHz) and power. We find that the microwave irradiation amplifies and maintains the precessional state of the eigenresonance within a larger field range. The experiments are discussed in comparison to micromagnetic as well as macrospin simulations utilizing the nonlinearized Landau-Lifshitz-Gilbert equation

Customer Relationship Management System a Case Study on Small-Medium-Sized Companies in North Germany

Customer relationship management is a common tool in large enterprises; yet it seems not to be successful with small- and medium-sized enterprises (SME). We conducted a survey to analyse the state-of-the-art customer relationship management systems and the degree of pervasion in SME. The survey covers 253 SMEs from North Germany and evaluates the available systems, desired and actually delivered functionality, integration in the Information Technology landscape, client satisfaction, and arguments about benefits and drawbacks of current CRM-systems. The main contribution of the chapter is improving the awareness of the importance that CRM has specifically for SMEs and benefits which SMEs can gain using CRM

Price Fluctuations and the Use of Bitcoin: An Empirical Inquiry

Over recent years, interest has been growing in Bitcoin, an innovation that has the potential to play an important role in e-commerce and beyond. The aim of our paper is to provide a comprehensive empirical study of the payment and investment features of Bitcoin, and their implications for the conduct of e-commerce. Since network externality theory suggests that the value of a network and its take-up are interlinked, we investigate both adoption and price formation. We discover that its returns are driven primarily by Bitcoin’s popularity, the sentiment expressed in newspaper reports on cryptocurrency, and total number of transactions. The paper also reports on the first global survey of merchants who have adopted this technology, and we model the share of sales paid for with this alternative currency, using both ordinary and Tobit regressions. Our analysis examines how country-, customer-, and company-specific characteristics interact with the proportion of sales attributed to Bitcoin. We find that company features, use of other payment methods, customers’ knowledge about Bitcoin, and the size of both the official and unofficial economy are significant determinants. The results will be of interest to traders who seek to understand factors driving prices and will help to inform vendors as to the most favorable circumstances for adopting the currency for online transactions