There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

비만아 부모의 돌봄 경험: q 방법론

Giant and isotropic magnetoresistance as huge as −53% was observed in magnetic manganese oxide La0.72Ca0.25MnOz films with an intrinsic antiferromagnetic spin structure. We ascribe this magnetoresistance to spin‐dependent electron scattering due to spin canting of the manganese oxide.

31p-S-4 Giant Magnetoresistance in Magnetic Manganese Oxide with Intrinsic Antiferromagnetic Spin Structure

Nanomaterials (NMs) are gaining significance in technological applications due to their tunable chemical, physical, and mechanical properties and enhanced performance when compared with their bulkier counterparts. This review presents a summary of the general types of NMs and provides an overview of the various synthesis methods of nanoparticles (NPs) and their functionalization via covalent or noncovalent interactions using different methods. It highlights the techniques used for the characterization of NPs and discusses their physical and chemical properties. Due to their unique properties, NMs have several applications and have become part of our daily lives. As a result, nanotoxicity research is gaining attention since some NPs are not easily degraded by the environment. Thus, this review also highlights research efforts into the fate, behavior, and toxicity of different classes of NMs in the environment.

Nanomaterials: Classification, properties, and environmental toxicities

Anisotropic electrical properties of 200 MeV Ag+15 ion irradiated manganite films

In this communication, we report the results of the studies on the grain boundary (GB) effect on the structural, microstructural and transport properties of nanostructured PrMnO3 (PMO) manganites synthesized by acetate precursor based sol – gel method. As synthesized PMO samples were sintered at various temperatures to understand the role of sintering temperature in modifying the structure – property correlations in the context of GB effects. Structural analysis using X-ray diffraction studies reveal the single phasic nature of all the PMO samples while TEM analysis reveals uniform particle size distribution with agglomeration effect observed in samples sintered at higher temperatures. SEM micrographs depict the increase in grain size with sharp grain boundaries in the samples sintered at a higher temperature. Size-dependent resistivity behavior of the PMO samples have been understood in the light of grain size modification and GB effect.

Grain boundary effects on the structural, microstructural and transport behavior of sol – gel grown PrMnO3 nanoparticles

The effect of Co-Ga paired substitution on the superconducting properties of YBa2Cu3O7-d (Y-123) has been investigated by X-ray diffraction, ac susceptibility,dc resistivity and oxygen content measurements. We report in this paper the results of our studies on the paired substitution of a magnetic and non-magnetic ion at Cu site in Y-123, while keeping the total dopant concentration fixed. The simultaneous substitution of Co and Ga at Cu site shows variation in the transition temperature (Tc), oxygen content and hole concentration as a function of change in the balance of magnetic (Co) and non-magnetic (Ga) concentration. Orthorhombicity (D), given as (b-a)/a, also varies as a function of increasing dopant concentration. The variation in Tc due to Co-Ga substitution is discussed in the light of dopant valency and hole filling mechanism.

Effect of Co-Ga paired substitution on superconductivity in YBa2Cu3O7-d

Thermal and laser irradiation effects on dielectric properties of zinc ferrite

The structural and superconducting properties of Y1−v−ηPrNCd{η}¨zCazBa2Cu3O7−δsystem are investigated using X-ray diffraction, ac susceptibility, dc resistivity, and oxygen content measurements. The effect of increasing Cd concentration substituting the Y-site in Y0.8Pr0.2Ba2Cu3O7-δ suppresses the superconducting transition temperature and lowers the hole concentration, unlike that of Ca substitution in Y0.8Pr0.2Ba2Cu3O7-δ which increasesTc due to hole doping by Ca. The suppression ofTc due to Cd substitution can be counterbalanced by simultaneous hole doping by Ca which increases the Tc with increasing Ca concentration. In spite of similarity in the ionic radii and valency, the role played by Cd and Ca substitution at the Y-site in the Y0.8Pr0.2Ba2Cu3O7-δ system is opposite in nature as Cd doping helps in Tc suppression due to the Pr effect, suggesting that Cd does not provide the necessary holes like Ca substitution which helps to increase the Tc by the hole doping mechanism.

Nikesh A. Shah

Papers

Anisotropic electrical properties of 200 MeV Ag+15 ion irradiated manganite films

Grain boundary effects on the structural, microstructural and transport behavior of sol – gel grown PrMnO3 nanoparticles

Effect of Co-Ga paired substitution on superconductivity in YBa2Cu3O7-d

Thermal and laser irradiation effects on dielectric properties of zinc ferrite

Effect of Cd and Cd-Ca substitution on the superconductivity in Y1-xPrxBa2Cu3O7-δ superconductor