Materials Literature
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In a real magnet, the relation between isothermal remanence Jr(H) and dc demagnetization remanence Jd(H) is expressed as δm(H)=[Jd(H)−Jr(∞)+2Jr(H)]/J(∞). It is believed that nonzero δm is due to the interactions between particles in the magnet. Using Pr2Fe14B as a sample, the relation is examined by the micromagnetic…
Over the past few years, bionanomaterial science has emerged as a new exciting field in which theoretical and experimental studies of structure and function of bionanomaterials have become a focus, and the importance of DNA, RNA, and peptides as bionanomaterials to the fundamental development in biology and nanomateri…
We have fabricated electronic devices based on single-walled boron nitride nanotubes (BNNTs). Our measurements indicate that all BNNTs are semiconducting, and p-doped. Temperature dependence of two terminal transport experiments suggests that at low drain fields, transport is dominated by thermionic emission over 250–…
Nano-silver doped silica films were deposited on glass slides using a sol-gel process and heat-treated at different temperatures. The films were characterized by ultraviolet-visible spectroscopy, x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), Rutherford backscattering spectrometry (RBS), and tr…
Porous silicon free-standing microcavity structures, with different layer designs, have been fabricated. Single microcavities show transmission resonances in the technologically relevant wavelength region of 1.55 μm with quality factors up to 3380. High-order cavities show sub-nm transmission peaks over the whole stop…
[reaction: see text] A mu-oxo-iron(III) dimer, [((phen)(2)(H(2)O)Fe(III))(2)(mu-O)](ClO(4))(4), is an efficient epoxidation catalyst for a wide range of alkenes, including terminal alkenes, using peracetic acid as the oxidant. Low catalyst loadings, in situ catalyst preparation from common reagents, fast reaction time…
Well-aligned indium oxide pyramids were synthesized on a Ni-coated silicon (100) substrate by a chemical vapor deposition. Scanning electron microscopy and x-ray diffraction investigations show that these pyramids present a tetragonal morphology and single-crystalline cubic bixbyite structure. The size control of the…
A magnetoelectric (ME) hybrid structure is constructed by an efficient coupling between magnetostrictive Terfenol-D (Tb0.27-0.30Dy0.73-0.70Fe1.90-1.95)/epoxy and piezoelectric lead–zirconate–titanate [Pb(Zr0.52Ti0.48)O3]/epoxy composites. Significant ME effect produced by the piezoelectric k31 coupling with the longit…
A large positive magnetic entropy change ΔSM is observed in the metallic antiperovskite Mn3GaC near its first-order metamagnetic transition temperature 159 K where the stoichiometric compound transforms from an antiferromagnetic to a canted ferromagnetic state accompanied by a discontinuous volume change of −0.46% wit…
We compare the electronic structure of differently fluorinated copper phthalocyanines (CuPC, CuPCF4, and CuPCF16) using x-ray photoemission spectroscopy and valence-band ultraviolet photoemission spectroscopy. Whereas the ionization potential (IP) is increased by more than 1 eV as a function of the degree of fluorinat…
We present a comprehensive comparative study of properties of BN and C nanotubes using a full potential linear combination of atomic orbitals approach, as well as a planewave pseudopotential method. This paper covers our results on the structural, mechanical, vibrational, and electronic properties, examining in detail…
In this Account strategies using zeolites as media to achieve chiral induction are presented. Diastereomeric excesses as high as 90% and enantiomeric excesses up to 78% have been obtained with selected systems within zeolites. The same systems show no asymmetric induction in solution. Chiral induction is dependent on…
Quantum confinement, magnetic-field effects, and laser coupling with the two low-lying states of electrons bound to donor impurities in semiconductors may be used to coherently manipulate the two-level donor system in order to establish the appropriate operational conditions of basic quantum bits (qubits) for solid-st…
In a recent letter Chicanne {\em et al.} [1] reported the experimental observation of the electromagnetic local density of states LDOS established by gold nanostructures. The obtained images have been compared with combinations of partial LDOSs defined in terms of the imaginary part of the Green-tensor ${\bf G}^I = [{…
The results of ac and dc magnetization and heat capacity measurements as a function of temperature (T = 1.8 to 300 K) are reported for a quasi-one-dimensional compound, Ca$_3$CuMnO$_6$, crystallizing in a triclinically distorted K$_4$CdCl$_6$-type structure. The results reveal that this compound undergoes antiferromag…
Spin coating is introduced as a simplified method to prepare model surfaces of cellulose. Prior to spin coating, trimethylsilyl cellulose (TMSC), a nonpolar derivative of cellulose, is synthesized in order to dissolve the otherwise immiscible cellulose. After the spin coating deposition of TMSC on an untreated silicon…
Electrochemical methods are used to inject charge into films of colloidal semiconductor nanocrystals of PbSe. The injection of electrons and holes into quantum confined states is confirmed by monitoring changes in the IR absorption spectrum. Holes are injected into the 1Sh state, causing a bleach of the 1Sh-1Se and 1S…
A review is given of recent neutron and x-ray scattering studies of the lead-oxide perovskite relaxor systems Pb(Zn1/3Nb2/3)O3-xPbTiO3 and Pb(Mg1/3Nb2/3)O3-xPbTiO3. X-ray measurements by Noheda et al. have established that these two systems exhibit nearly identical phase diagrams in which a rhombohedral-monoclinic-tet…
A theory of spin manipulation of quasi-two-dimensional (2D) electrons by a time-dependent gate voltage applied to a quantum well is developed. The Dresselhaus and Rashba spin-orbit coupling mechanisms are shown to be rather efficient for this purpose. The spin response to a perpendicular-to-plane electric field is due…
The computational Projective Dynamics method is used to analyze simulations of magnetization reversal in nanoscale magnetic pillars. It is shown that this method can be used to determine the magnetizations corresponding to the metastable minimum and saddle point in the free energy, and the free-energy barrier associat…