Electric-field-controlled magnetism can boost energy efficiency in widespread applications. However, technologically, this effect is facing important challenges: mechanical failure in strain-mediated piezoelectric/magnetostrictive devices, dearth of room-temperature multiferroics, or stringent thickness limitations in electrically charged metallic films. Voltage-driven ionic motion (magneto-ionics) circumvents most of these drawbacks while exhibiting interesting magnetoelectric phenomena. Nevertheless, magneto-ionics typically requires heat treatments and multicomponent heterostructures. Here we report on the electrolytegated and defect-mediated O and Co transport in a Co 3 O 4 single layer which allows for room-temperature voltage-controlled ON−OFF ferromagnetism (magnetic switch) via internal reduction/oxidation processes. Negative voltages partially reduce Co 3 O 4 to Co (ferromagnetism: ON), resulting in graded films including Co-and O-rich areas. Positive bias oxidizes Co back to Co 3 O 4 (paramagnetism: OFF). This electric-field-induced atomic-scale reconfiguration process is compositionally, structurally, and magnetically reversible and self-sustained, since no oxygen source other than the Co 3 O 4 itself is required. This process could lead to electric-field-controlled device concepts for spintronics.

Magnetic data storage and magnetically actuated devices are conventionally controlled by magnetic fields generated using electric currents. This involves significant power dissipation by Joule heating effect. To optimize energy efficiency, manipulation of magnetic information with lower magnetic fields (i.e., lower electric currents) is desirable. This can be accomplished by reducing the coercivity of the actuated material. Here, a drastic reduction of coercivity is observed at room temperature in thick (≈600 nm), nanoporous, electrodeposited Cu-Ni films by simply subjecting them to the action of an electric field. The effect is due to voltage-induced changes in the magnetic anisotropy. The large surface-area-to-volume ratio and the ultranarrow pore walls of the system allow the whole film, and not only the topmost surface, to effectively contribute to the observed magnetoelectric effect. This waives the stringent "ultrathin-film requirement" from previous studies, where small voltage-driven coercivity variations were reported. This observation expands the already wide range of applications of nanoporous materials (hitherto in areas like energy storage or catalysis) and it opens new paradigms in the fields of spintronics, computation, and magnetic actuation in general.is conventionally done by localized magnetic fields (generated via electromagnetic induction) or by spin-polarized electric currents (spin-transfer torque). [2,4] Both principles require of relatively high electric currents and therefore involve significant loss of energy in the form of heat dissipation (Joule effect). For example, the currents needed to operate conventional magnetic random-access memories (MRAMs) are of the order of 10 mA, whereas spin-transfer torque MRAMs require currents of at least 0.5 mA. This is still a factor five times larger than the output currents delivered by highly miniaturized metal-oxide-semiconductor field-effect transistors. [5] Replacement of electric currents by electric fields would drastically contribute to reduce the overall power consumption in these and other devices.Several approaches to tailor magnetism by means of an electric field have been proposed so far: (i) strain-mediated magnetoelectric coupling in piezoelectric-magnetostrictive composite materials, [6,7] (ii) multiferroic materials in which the ferroelectric and ferromagnetic order parameters are coupled to each other, [8] and (iii) electric-field induced oxidation-reduction transitions (magnetoionics). [9,10] However, each of these approaches faces some drawbacks, e.g., (i) clamping effects with the substrate, need of epitaxial interfaces, and risk of fatigue-induced mechanical failure; (ii) the dearth of available multiferroic materials and the reduced strength of magnetoelectric coupling, even at low temperatures; and (iii) precise control of the chemical

Este trabalho objetivou conhecer as situações que se apresentam ao estudante de Medicina como angustiantes durante a sua formação e os fatores que ele identifica como originários desse sentimento. Foi empregada uma abordagem etnográfica, utilizando-se entrevistas semi-estruturadas, observação e grupos de discussão. Os dados foram analisados por meio de Análise de Conteúdo. Os alunos identificaram a dissociação entre o ciclo básico e o profissionalizante como responsável pela angústia suscitada em face do primeiro contato com o paciente, além de apresentarem estresse psicológico por terem que trabalhar com a dor e o sofrimento. Os discentes identificaram, também, como fator estressante o fato de que sua aprendizagem implica a utilização de outro ser humano. Além disso, em algumas situações, a dificuldade de relacionamento com os professores é apontada como geradora de angústia.

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Magneto-ionics, understood as voltage-driven ion transport in magnetic materials, has largely relied on controlled migration of oxygen ions. Here, we demonstrate room-temperature voltage-driven nitrogen transport (i.e., nitrogen magneto-ionics) by electrolyte-gating of a CoN film. Nitrogen magneto-ionics in CoN is compared to oxygen magneto-ionics in Co3O4. Both materials are nanocrystalline (face-centered cubic structure) and show reversible voltage-driven ON-OFF ferromagnetism. In contrast to oxygen, nitrogen transport occurs uniformly creating a plane-wave-like migration front, without assistance of diffusion channels. Remarkably, nitrogen magneto-ionics requires lower threshold voltages and exhibits enhanced rates and cyclability. This is due to the lower activation energy for ion diffusion and the lower electronegativity of nitrogen compared to oxygen. These results may open new avenues in applications such as brain-inspired computing or iontronics in general.

A synergetic approach to enhance magnetoelectric effects (i.e., control of magnetism with voltage) and improve energy efficiency in magnetically actuated devices is presented. The investigated material consists of an ordered array of Co−Pt microdisks, in which nanoporosity and partial oxidation are introduced during the synthetic procedure to synergetically boost the effects of electric field. The microdisks are grown by electrodeposition from an electrolyte containing an amphiphilic polymeric surfactant. The bath formulation is designed to favor the incorporation of oxygen in the form of cobalt oxide. A pronounced reduction of coercivity (88%) and a remarkable increase of Kerr signal amplitude (60%) are observed at room temperature upon subjecting the microdisks to negative voltages through an electrical double layer. These large voltage-induced changes in the magnetic properties of the microdisks are due to (i) the high surface-area-to-volume ratio with ultranarrow pore walls (sub-10 nm) that promote enhanced electric charge accumulation and (ii) magneto-ionic effects, where voltage-driven O 2− migration promotes a partial reduction of CoO to Co at room temperature. This simple and versatile procedure to fabricate patterned "nano-in-micro" magnetic motifs with adjustable voltage-driven magnetic properties is very appealing for energy-efficient magnetic recording systems and other magnetoelectronic devices.

ArtigoTrends Psychol., Ribeirão Preto, vol. 26, nº 2, p. 795-805 -Junho/2018 Orcid.org/0000-0001-7255-9979 ------------------------------------------- -------------------------------------------------- ResumoEsta pesquisa objetivou conhecer as angústias vivenciadas pelos enfermeiros no trabalho com pacientes em risco ou em processo de morte em uma unidade hemato-oncológica. Estudo clínico-qualitativo, realizado por meio de entrevistas individuais. Participaram desta pesquisa 06 enfermeiros da unidade hemato-oncológica de um hospital universitário. Os resultados foram reunidos em cinco categorias, as quais remetem à perda da autonomia profi ssional quando o enfermeiro se depara com a difi culdade de pensar o seu próprio trabalho. O trabalho com a criança com câncer parece ser símbolo de uma angústia maior em lidar com a morte. Ao mesmo tempo em que a melhora ou a esperança de cura dá motivação ao enfermeiro, a morte do paciente infantil tem o signifi cado de impotência, tristeza e desesperança. Os enfermeiros, ao longo do processo de trabalho, têm insights sobre como a sua relação com o trabalho poderia ser melhorada, porém, no momento do sofrimento, a preocupação dos enfermeiros não foi ouvida. Há a necessidade de que instituições de saúde, equipes e o próprio enfermeiro percebam esse profi ssional como um sujeito ético, necessitando refl etir seu trabalho para que haja possibilidade de planejar alguma forma de digerir a angústia do trabalho.Keywords: Atitude frente à morte, Enfermagem, Psicologia da Saúde, estresse psicológico. Psychological Distress Experienced by Nurses who Work with Patients in Death Process: A Clinical-Qualitative Study AbstractThis research aimed to know the anguish experienced by nurses who work with patients in risk or in dying process in a hematology-oncology unit. A clinical-qualitative study, conducted through individual

Voltage control of magnetism through electric field‐induced oxygen motion (magneto‐ionics) could represent a significant breakthrough in the pursuit for new strategies to enhance energy efficiency in magnetically actuated devices. Boosting the induced changes in magnetization, magneto‐ionic rates and cyclability continue to be key challenges to turn magneto‐ionics into real applications. Here, it is demonstrated that room‐temperature magneto‐ionic effects in electrolyte‐gated paramagnetic Co3O4 films can be largely increased both in terms of generated magnetization (6 times larger) and speed (35 times faster) if the electric field is applied using an electrochemical capacitor configuration (utilizing an underlying conducting buffer layer) instead of placing the electric contacts at the side of the semiconductor (electric‐double‐layer transistor‐like configuration). This is due to the greater uniformity and strength of the electric field in the capacitor design. These results are appealing to widen the use of ion migration in technological applications such as neuromorphic computing or iontronics in general.