Magnetization switching

Magnetic switches (reed switches) The most widely used perimeter sensor. They are typically used to protect doors, as well as windows that can be opened (windows that cannot be opened are more typically protected by foil alarms). 

Nitroxides are the most common of the oxygen-centred biradicals to be reported. As a model for spin-crossover molecules, the nitronyl nitroxide (105) was prepared and by oxidation with PbC>2 afforded the triplet biradical (106) which was characterized by ESR (Scheme 15).242 The one-electron oxidation of (105) afforded the singlet cation (107) which was seen to exist in equilibrium with (106) in solution. The authors claim that pH-controlled interconversion between two species of different spin multiplicities in this way may provide die basis for novel magnetic switches or pH sensors. The N.N-dialkylamino nitronyl nitroxides (108) were prepared and afforded die diplet-state biradical cation species by one-electron oxidation with iodine.243 The authors propose that, by the similarity of die electronic structures, diese structures can be regarded as hetero-analogues of trimethylenemethane. A paper confirms die conversion of 3,3-dimethyldioxetane into die corresponding ring-opened 1,2-diol but refutes the... 

Lu Z, Prouty MD, Guo Z et al (2005) Magnetic switch of permeability for polyelectrolyte microcapsules embedded with Co Au nanoparticles. Langmuir 21 2042-2050... 

In this section, we propose a new switching unit, in which two radicals are placed in the same aryl unit and Jt-conjugated chain is extended from 2- and 5-positions of the thiophene ring in one aryl unit of the diarylethene [70]. The photochromic reactivity and magnetic switching of the new diarylethene derivatives will be discussed. 

Figure 23. Current induced magnetization switching (spin transfer driven) (a) resistance vs.

The steel ball is dropped on the upper roller by cutting off the magnet switch. 

Fig. 7. Magnetic field-counter arrangement in a magnetic switching experiment [Eq. (3.25)]...

Until much improved flux-to-background ratios are available it does not seem likely that much progress will be made with this type of experiment either by observation of total diffuse cross-sections, magnetic-switching cross-sections, or polarization analysis measurement of paramagnetic cross-sections, and conventional form factor measurement of paramagnetic as well as of magnetically ordered systems will be much more fruitful. 

Nordstrom L, Singh DJ (1996) Noncollinear intra-atomic magnetism. Phys Rev Lett 76 4420-4423 Nowak U, Chantrell RW, Keimedy EC (2000) Monte Carlo simulation with time step quantification in terms of Langevin dynamies. Phys Rev Lett 84 163-166 Nowak U, Hinzke D (1999) Magnetization switching in small ferromagnetic particles Nucleation and coherent rotation. J Appl Phys 85 4337-4339... 

The process controller also has a pressure switch for the process control box with attendant power supply and an LCD pressure readout for the box with its own power supply, which is controlled by a magnetic switch. 

The controller has five ports, two for pressure and three for wire. The box also contains a nine volt battery supply with a magnetic switch for a digital voltmeter, and a variety of terminal block connectors. 

---