[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ferromagnetic materials

Interpretation of X-ray Powder Diffraction Patterns . By H. Lipson and H. Steeple. Pp. viii + 335 + 3 plates. (Mac-millan: London; St Martins Press: New York, May 1970.) £4.

X-Ray Diffraction

Platinum-based nanostructured materials: synthesis, properties, and applications.

Designer platinum nanoparticles: Control of shape, composition in alloy, nanostructure and electrocatalytic property

The whole is sometimes more than the sum of its parts. Certainly it is true for ordered mesoscopic materials, when the assembly of particles acquires properties which are not the intrinsic ones of the constituent particles. One of the best illustrative examples is the case of photonic crystals – attractive optical materials for controlling and manipulating the fl ow of light. Since the appearance of seminal papers in 1987 the number of research papers devoted to the subject, began to grow exponentially. [ 1–2 ] Three-dimensional photonic crystals offer additional features compared to 1D (gratings, multilayers) and 2D cases, possibly leading to new device concepts (e.g., for optical computing), but manufacturing problems are still far from being solved. While 2D structures could be created by techniques adapted from semiconductor industry, this is less obvious for the 3D case, and as an alternative self-assembly approaches are considered to have a great potential. [ 3 ] The effi ciency of the latter approach is demonstrated long ago by the very existence of prototypical photonic crystals – gem opals. In the case of photonic materials, the crystalline structure of individual subunits is practically of no relevance. The target design properties are not only defi ned by the average mesoscopic structure, but by its specifi c realization, including random or correlated defects (non-monodisperse subunits, vacancies, dislocations, stacking faults, etc.). The mesoscale can be probed by imaging-related or diffraction-related methods. The fi rst family of techniques was exclusively limited to surface imaging, namely to scanning electron microscopy and a replica-technique variety of transmission electron microscopy. [ 4–6 ]

High‐Resolution Transmission X‐ray Microscopy: A New Tool for Mesoscopic Materials

Templating of electrodeposited platinum group metals as a tool to control catalytic activity

Role of Electrode Reaction Kinetics in Self-Ordering of Porous Anodic Alumina

http://www.elch.chem.msu.ru/rus/roslyakov.pdf

Tuning the microstructure and functional properties of metal nanowire arrays via deposition potential

Mass-transport properties of anodic alumina membranes exploited in a number of technological areas are strongly affected by the real pore structure and arrangement of channels that can split or terminate during the anodization process. This paper focuses on the investigation of pore branching and rearrangement caused by voltage variation in the course of the anodic oxidation of aluminum. Gas-transport measurements were utilized for the quantitative determination of an effective through porosity of multilayer anodic alumina membranes with branched channels obtained by variation of anodization voltage. It was shown that on decrease of anodization voltage a branching of pores occurs, while an increase of anodization voltage leads to the termination of some of the pores with an increase in the diameter of others. Gas permeance measurements combined with electron microscopy unambiguously prove dead-end pore formation on voltage increase, while no pore merging appears. This generally affects any mass-transport properties and applications of anodic alumina membranes as the delivery of any species (e.g. ions, gas molecules, etc) through the blocked channels is impossible.

http://iopscience.iop.org/article/10.1088/0957-4484/23/33/335601/pdf

Kirill S. Napolskii

Papers

High‐Resolution Transmission X‐ray Microscopy: A New Tool for Mesoscopic Materials

Templating of electrodeposited platinum group metals as a tool to control catalytic activity

Role of Electrode Reaction Kinetics in Self-Ordering of Porous Anodic Alumina

Tuning the microstructure and functional properties of metal nanowire arrays via deposition potential

Permeability of anodic alumina membranes with branched channels.