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

We report the effect of Cu-doping on the dielectric behavior of NdMn1−xCuxO3 (NMCO); x = 0.0 – 0.05, manganites. It is observed that, dielectric constant (e′) decreases with Cu (x) concentration which has been understood on the basis of modifications in grain morphology and double exchange (DE) interaction between Mn3+ and Mn4+. Also, effect of grain boundary (GB) density on the dielectric response is studied using cole-cole plots.

Studies on the dielectric behavior of Cu-doped NdMnO3

In this communication, structure and charge, conduction mechanisms have been understood for sol–gel-grown nanostructured La0.6Nd0.1Sr0.3MnO3 (LNSMO) manganites prepared at different process temperatures under air and oxygen environments. Obtained X-ray diffraction patterns of all the samples were analysed using Rietveld refinements and obtained structural lattice parameters have been discussed in correlation with resistivity behaviour of the samples. Observed low temperature resistivity upturn behaviour has been examined in the context of electron–electron scattering mechanism. Metallic and insulating/semiconducting behaviours of all the nanostructured LNSMO manganites have been understood by using various models and mechanisms. Magnetoresistance isotherms have also been theoretically fitted and separate grain and grain boundary contributions have been studied for LNSMO manganite samples. All obtained fitting parameters have been discussed in the context of role of applied magnetic field, process temperature and annealing environment.

Charge conduction mechanisms and MR behaviour of sol–gel-grown nanostructured La0.6Nd0.1Sr0.3MnO3 manganites

Transport Properties of Calcium Doped YMnO3 Thin Film

Effect of silica on structural and optical properties of cobalt ferrite nanoparticles is investigated. Silica matrix helps to reduce nanoparticle agglomeration. X-ray diffraction (XRD) and UV–Visible (UV–Vis) spectroscopic techniques are employed. XRD reveals pure phase formation with material density varying from 2.37 g cm−3 to 0.85 g cm−3. Energy band gap shows an escalation (2.03 eV to 4.89 eV) for change in silica from 0% to 90%. An empirical formula for refractive index as μ = A(silica content)2+B(silica content)+C has been derived using theoretical fit. With increase in silica content, the refractive index, optical dielectric constant and dielectric susceptibility show decrements from 2.65 to 1.83, 6.0225 to 2.3489 and 0.4795 to 0.1870 respectively. The reflectivity, absorption coefficient, molar refractive index, molar electronic polarizability, reflection loss, polaron radius and optical basicity also show reduction. Dielectric polarizability, transmission coefficient and oxygen packing density show increment from 0.33 Å 3 to 11.19 Å 3, 0.6606 to 0.8416 and 40.2114 to 34.2266. Ionic concentration of silica, metallization criterion also show similar incremental trend. Observed effects have been attributed to the change in interparticle interactions, density and microstructure of the samples. Swift changes in parameters indicate their fine tuning through optimum magnitude of silica. 

Effect of silica matrix on structural and optical properties of cobalt ferrite nanoparticles

The synthesis of nanoparticles using ecofriendly way is an interesting area in advance nanotechnology. Silver (Ag) nanoparticles are usually synthesized by chemicals route, which are quite flammable and toxic in nature. This study deals with a biosynthesis process (environment friendly) of silver nanoparticles using Bambusa arundinacea leaves for its antibacterial activity. The formation and characterization of AgNPs was confirmed by UV-Vis spectroscopy. Silver nanoparticles were successfully synthesized from AgNO3 through a simple green route using the latex of Bambusa arundinacea leaves as reducing as well as capping agent. Scanning Electron Microscopy (SEM) study indicates the formation of grains (particles) with different size and shape.

Nikesh A. Shah

Papers

Studies on the dielectric behavior of Cu-doped NdMnO3

Charge conduction mechanisms and MR behaviour of sol–gel-grown nanostructured La0.6Nd0.1Sr0.3MnO3 manganites

Transport Properties of Calcium Doped YMnO3 Thin Film

Effect of silica matrix on structural and optical properties of cobalt ferrite nanoparticles

Green synthesis of silver nanoparticle using Bambusa arundinacea leaves