Hexagonal ferrites: A review of the synthesis, properties and applications of hexaferrite ceramics

Biocompatibility, Pharmaceutical and Biomedical Applications L. Harivardhan Reddy,†,‡ Jose ́ L. Arias, Julien Nicolas,† and Patrick Couvreur*,† †Laboratoire de Physico-Chimie, Pharmacotechnie et Biopharmacie, Universite ́ Paris-Sud XI, UMR CNRS 8612, Faculte ́ de Pharmacie, IFR 141, 5 rue Jean-Baptiste Cleḿent, F-92296 Chat̂enay-Malabry, France Departamento de Farmacia y Tecnología Farmaceútica, Facultad de Farmacia, Campus Universitario de Cartuja s/n, Universidad de Granada, 18071 Granada, Spain ‡Pharmaceutical Sciences Department, Sanofi, 13 Quai Jules Guesdes, F-94403 Vitry-sur-Seine, France

Magnetic nanoparticles: design and characterization, toxicity and biocompatibility, pharmaceutical and biomedical applications.

We developed means to produce wafer scale, high-quality graphene films as large as 3 in. wafer size on Ni and Cu films under ambient pressure and transfer them onto arbitrary substrates through instantaneous etching of metal layers. We also demonstrated the applications of the large-area graphene films for the batch fabrication of field-effect transistor (FET) arrays and stretchable strain gauges showing extraordinary performances. Transistors showed the hole and electron mobilities of the device of 1100 ± 70 and 550 ± 50 cm2/(V s) at drain bias of −0.75 V, respectively. The piezo-resistance gauge factor of strain sensor was ∼6.1. These methods represent a significant step toward the realization of graphene devices in wafer scale as well as application in optoelectronics, flexible and stretchable electronics.

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Wafer-Scale Synthesis and Transfer of Graphene Films

https://shell.cas.usf.edu/~phanm//PMS.pdf

Giant magnetoimpedance materials: Fundamentals and applications

Experimental results on the bistable resistive memory switching in submicron sized NiO memory cells are presented. By using a current-bias method, intermediate resistance states and anomalous resistance fluctuations between resistance states are observed during the resistive transition from high resistance state to low resistance state. They are interpreted to be associated with filamentary conducting paths with their formation and rupture for the memory switching origin in NiO. The experimental results are discussed on the basis of filamentary conductions in consideration of local Joule heating effect.

Electrical observations of filamentary conductions for the resistive memory switching in NiO films

Amorphous glass-covered magnetic wires: Preparation, properties, applications

During the preparation process of the glass-covered magnetic amorphous wires, axial, radial, and azimuthal internal stresses are induced, determining their magnetic properties. We have proposed a calculation method of the internal stresses induced during the solidification of the metal and during the cooling from the solidification temperature to room temperature due to the difference between the thermal expansion coefficients of metal and glass. For ${\mathrm{Fe}}_{77.5}$${\mathrm{Si}}_{7.5}$${\mathrm{B}}_{15}$ glass-covered amorphous wires we found internal stresses of about ${10}^{9}$ Pa. The values and distribution of these stresses depend on the radius of the metal and on the thickness of the glass cover. The stress distribution coupled with the specific high positive magnetostriction leads to an easy axes distribution associated with a magnetic domain structure consisting of a cylindrical inner core with axial magnetization and a cylindrical outer shell with radial magnetization. The inner core leads to the appearance of a large Barkhausen jump at low axial fields. We have calculated the ratio ${\mathit{M}}_{\mathit{r}}$/${\mathit{M}}_{\mathit{s}}$ (the reduced remanence) as being of about 0.75\char21{}0.80. Magnetic measurements performed on samples prepared by us confirm the existence of the large Barkhausen jump but with a reduced remanence of about 0.95 that suggests the existence of a supplementary axial tensile stress. The dependence of the reduced remanence on external tensile stresses for wires covered by glass and after the glass removal confirms the existence of the supplementary stress whose value was estimated as being of the order of ${10}^{8}$ Pa.

Internal stress distribution in glass-covered amorphous magnetic wires

, Phone: þ34 913349051, Fax: þ34 913720623Recognizing the importance of magnetic thin wires for scienceand technology, the 6th International Workshop on MagneticWires was held on 6–7 July 2010, in Bodrum, Turkey. A widerange of topics were addressed from technological problems ofmicro-andnanowirefabrication,toadvancedphysicaleffectsandnovel applications. Furthermore, critical discussions on thepresent state of knowledge and future trends arose during thePanel Session on microwires. In the present report, the mainaspects addressed at the Discussion Panel and at workshoppresentationsaresummarizedwiththeaimtostatethepresentandfuture perspectives on these wire systems. This report is focusedupon four topics chosen for broad discussions at the Panel:Fabrication and processing, Magnetization reversal and Dynam-ics, High-frequency properties, and Technological applications.

Horia Chiriac

Papers

Amorphous glass-covered magnetic wires: Preparation, properties, applications

Internal stress distribution in glass-covered amorphous magnetic wires

On the state-of-the-art in magnetic microwires and expected trends for scientific and technological studies

Magnetoelastic anisotropy of amorphous microwires

Magnetic properties and giant magnetoimpedance in a CoFeSiB glass-covered microwire