Core/Shell Nanoparticles: Classes, Properties, Synthesis Mechanisms, Characterization, and Applications

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

http://files.janapv.webnode.cz/200000097-8a03f8afdf/ex_bias_nano.pdf

Exchange bias in nanostructures

We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

Mn3O4-Graphene Hybrid as a High Capacity Anode Material for Lithium Ion Batteries

https://www.andrew.cmu.edu/user/dl0p/laughlin/pdf/PMS.pdf

Amorphous and nanocrystalline materials for applications as soft magnets

/pdf/nanosseguranca-para-inovacao-sustentavel-a-avaliacao-da-2zvhkwlh.pdf

Nanossegurança para inovação sustentável: a avaliação da toxicidade e ciclo de vida de um nanoproduto é essencial para garantir que a sua produção e aplicações prosperem; sem provocar impactos negativos aos trabalhadores, consumidores e ao meio ambiente

Apparent split between magnetic and structural phase transitions in epitaxial MnAs films

Magnetic and Magnetotransport Properties of Nanostructured Magnetic Materials

In this paper, the exchange bias effect in Fe/EuTe(111) bilayers prepared by molecular beam epitaxy (MBE) is investigated by SQUID. For cooling fields from 2 to 70 kOe, only positive shifts was found of the magnetic hysteresis loops. This result indicates antiferromagnetic coupling between the ferromagnetic (F) and the antiferromagnetic (AF) layer at the Fe/EuTe(111) interface independently of the applied cooling field. Fe/EuTe bilayers prepared on EuTe(111) surfaces with stoichiometry (Eu:Te = 2.1) and, consequently, magnetic order altered by Ar-sputtering do not present exchange bias.

Positive exchange bias in Fe on antiferromagnetic semiconductor EuTe

Humanity is experiencing a moment of great uncertainty. This is not the first time a pandemic threatens the lives of millions of people. However, the speed with which governments and scientists are reacting to events is unprecedented. In an incredibly short time after the discovery of the virus, public health measures were implemented, and the development of defences in the form of public policies, medical therapies, and vaccines began. At this precarious moment, when the proliferation of information (and misinformation) from a variety of sources contribute to the spread of panic, universities and the scientific community emerge as the best and most reliable sources of information. It is only highly qualified specialists who can truly address the pandemic and its terrible economic, political, and public health consequences.

/pdf/towards-the-other-side-of-complexity-values-and-decisions-in-4to2d94n84.pdf

Marcelo Knobel

Papers

Nanossegurança para inovação sustentável: a avaliação da toxicidade e ciclo de vida de um nanoproduto é essencial para garantir que a sua produção e aplicações prosperem; sem provocar impactos negativos aos trabalhadores, consumidores e ao meio ambiente

Apparent split between magnetic and structural phase transitions in epitaxial MnAs films

Magnetic and Magnetotransport Properties of Nanostructured Magnetic Materials

Positive exchange bias in Fe on antiferromagnetic semiconductor EuTe

Towards the Other Side of Complexity: Values and Decisions in a Time of Uncertainty