Luminescent particle and method of detecting a biological entity using a lumiscent particle

The invention provides a luminescent particle ( 10 ) and a method of detecting a biological entity using a luminescent particle, the luminescent particle comprising a core area ( 20 ) and a shell area ( 30 ), the core area ( 20 ) being covered by the shell area ( 30 ), the core area ( 20 ) conferring a luminescent behavior on the luminescent particle ( 10 ) for at least one excitation wavelength and for at least one emission wavelength by means of a nanocrystal material ( 21 ), and the shell area ( 30 ) being provided such that it realizes an antireflective coating ( 31 ) of the core area ( 20 )

Explanation for the leakage current in polycrystalline-silicon thin-film transistors made by Ni-silicide mediated crystallization

\u3cp\u3eThe source of the leakage current in polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) made by Ni-mediated crystallization has been investigated. Studies of TFTs and of the crystallization process by in situ transmission electron microscopy show that the crystallization process is a two-stage process and that the cause of the leakage problem is associated with incomplete crystallization of amorphous-Si. By removing the last pockets of amorphous-Si, for instance, by long anneals, poly-Si TFTs can be made with adequately low leakage current <1 pA/μm (at a source-drain voltage of 5 V) for display applications, despite the presence of Ni up to 2.5×10 \u3csup\u3e19\u3c/sup\u3eatoms/cm\u3csup\u3e3\u3c/sup\u3e.\u3c/p\u3

Comment on Particle-Size Effects on the Value of Tc of MnFe2O4 : evidence for Finite-Size Scaling

We show that a nonequilibrium cation distribution is the likely explanation for the 47-K rise in the Curie temperature of ultrafine MnFe2O4 particles found by Kulkarni et al. This nonequilibrium cation distribution is argued to be caused, in part, by oxidation of Mn2+ to Mn3+ due to heating of the particles during the experiments performed by Kulkarni et al. to determine the Curie temperature

Thermally assisted reversal of exchange biasing in NiO and FeMn based systems

The stability of the exchange bias field Heb has been studied for magnetron sputtered NiO/Ni66Co18Fe16 and Ni66Co18Fe16/FeMn bilayers. A forced antiparallel alignment of the ferromagnetic magnetization to Heb results in a gradual decrease of Heb as a function of time for NiO as well as FeMn based samples. The observed decrease of Heb increases with temperature and is interpreted as a thermally assisted reversal of magnetic domains in the antiferromagnetic layer

On the construction of an Fe3O4 based all-oxide spin-valve

The progress made in constructing an all-oxide spin valve based on the intrinsic, fully spin-polarized electron transport in Fe3O4 is discussed. Two possible oxidic spacer layers, MgO and Mn3O4, have been investigated. Interlayer coupling studies indicate that MgO is the more suitable spacer layer of the two. Thus far a limited magnetoresistive effect 0.4% is found in the all oxide, Fe3O4-based, spin-valves which we have made. Possible causes for this low magnetoresistive effect are discussed

Magnetite Fe3-deltaO4 : a stoichiometry and structure analysis of MBE grown thin films using NO2 as the oxidising source

Epitaxial single crystalline films of iron oxides have been grown on MgO(100) substrates by means of MBE. Natural Fe or 57Fe was evaporated from alumina crucibles, and oxidised simultaneously with a dosed flux of NO2. The resulting oxide layers have been characterised in situ with RHEED, LEED, XPS, and AES. RHEED intensity oscillations, observed during deposition of the oxides, indicate a layer-by-layer growth for all substrate temperatures between 373 and 673 K. A stoichiometry analysis with CEMS, performed ex situ, shows that it is straightforward to prepare both the stable magnetite Fe3O4 and the metastable maghemite Fe3-dO4 phases. Moreover, also al1 solid solutions in between these two extreme phases, i.e. Fe3-dO4 with

Difference between blocking and néel temperatures in the exchange biased Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e/CoO system

\u3cp\u3eThe blocking temperature T\u3csub\u3eB\u3c/sub\u3e has been determined as a function of the antiferromagnetic layer thickness in the Fe\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e/CoO exchange biased system. For CoO layers thinner than 50 Å, T\u3csub\u3eB\u3c/sub\u3e is reduced below the Néel temperature T\u3csub\u3eN\u3c/sub\u3e of bulk CoO (291 K), independent of crystallographic orientation or film substrate (α-Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e, SrTiO\u3csub\u3e3\u3c/sub\u3e, and MgO). Neutron diffraction studies show that TB does not track the CoO ordering temperature and, hence, that this reduction in T\u3csub\u3eB\u3c/sub\u3e does not arise from finite-size scaling. Instead, the ordering temperature of the CoO layers is enhanced above the bulk TN for layer thicknesses ≲100Å due to the proximity of magnetic Fe3O4 layers.\u3c/p\u3