Emergent magnetic structures and dynamics in thin films: a review of some recent results

2020 ◽  
Vol 98 (9) ◽  
pp. 825-833
Author(s):  
K. De’Bell

The emergence of mesoscopic structures and the role of slow dynamics in thin magnetic films is an area of considerable interest. The role played by defect mediated dynamic processes is a current area of experimental and theoretical research that is essential to the understanding of the properties of these films. This research is driven by both the potential applications of thin magnetic films, and the fundamental questions and new physics that they point to. This brief review provides an overview of some recent experimental work on both epitaxial magnetic films and on meta-material magnetic films. An overview of some corresponding results from theory and simulation studies is also given. The article concludes with a summary and some forward-looking speculations and questions regarding these systems.

SPIN ◽  
2012 ◽  
Vol 02 (03) ◽  
pp. 1240002 ◽  
Author(s):  
PEDRAM KHALILI AMIRI ◽  
KANG L. WANG

Electric-field-control of magnetism can dramatically improve the energy efficiency of spintronic devices and enhance the performance of magnetic memories. More generally, it expands the range of applications of nonvolatile spintronic devices, by making them energetically competitive compared to conventional semiconductor solutions for logic and computation, thereby potentially enabling a new generation of ultralow-power nonvolatile spintronic systems. This paper reviews recent experiments on the voltage-controlled magnetic anisotropy (VCMA) effect in thin magnetic films, and their device implications. The interfacial perpendicular anisotropy in layered magnetic material stacks, as well as its modulation by voltage, are discussed. Ferromagnetic resonance experiments and VCMA-induced high-frequency magnetization dynamics are reviewed. Finally, we discuss recent progress on voltage-induced switching of magnetic tunnel junction devices and its potential applications to magnetic random access memory (MRAM).


1993 ◽  
Vol 07 (16n17) ◽  
pp. 2981-3002 ◽  
Author(s):  
M.W. LONG

The concepts relevant to frustrated antiferromagnets are briefly reviewed. Antiferromagnets are classified according to their symmetry groups, with non-trivial point groups leading to the possibility of multiple-Q antiferromagnetism. The role of residual degeneracy is highlighted and the manner in which this degeneracy is lifted is discussed. The physical phenomena in competition within frustrated magnets, and the states that they prefer, yield ongoing theoretical research, and the way neutron scattering can be used, in conjunction with the application of pressure and magnetic fields, to determine which of the possible magnetic structures is stabilised is under experimental scrutiny. Multiple-Q antiferromagnetism finds varied and often exotic spin states with similar energies, and as such is the setting in which phase transitions between different magnetic states can be studied.


Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.


2020 ◽  
pp. 82-86
Author(s):  
R. F.o. Veliev

A current theoretical and practical legal basis for creation of regulatory acts in the Russian Federation is discussed. A current relationship between the issued regulatory acts and some criteria of legal norm classification is shown. Legalization of the President address to the Parliament of the Russian Federation as a substantial element of the legal norm-making in a democratic state is revealed.


2018 ◽  
Author(s):  
Lorraine Tudor Car ◽  
Bhone Myint Kyaw ◽  
Josip Car

BACKGROUND Digital technology called Virtual Reality (VR) is increasingly employed in health professions’ education. Yet, based on the current evidence, its use is narrowed around a few most applications and disciplines. There is a lack of an overview that would capture the diversity of different VR applications in health professions’ education and inform its use and research. OBJECTIVE This narrative review aims to explore different potential applications of VR in health professions’ education. METHODS The narrative synthesis approach to literature review was used to analyse the existing evidence. RESULTS We outline the role of VR features such as immersion, interactivity and feedback and explain the role of VR devices. Based on the type and scope of educational content VR can represent space, individuals, objects, structures or their combination. Application of VR in medical education encompasses environmental, organ and micro level. Environmental VR focuses on training in relation to health professionals’ environment and human interactions. Organ VR educational content targets primarily human body anatomy; and micro VR microscopic structures at the level of cells, molecules and atoms. We examine how different VR features and health professional education areas match these three VR types. CONCLUSIONS We conclude by highlighting the gaps in the literature and providing suggestions for future research.


2017 ◽  
Vol 29 (2) ◽  
pp. 1-9 ◽  
Author(s):  
Sudip Bhattacharjee ◽  
Mario J. Maletta ◽  
Kimberly K. Moreno

ABSTRACT This study replicates Bhattacharjee, Maletta, and Moreno (2007), who find that audit preparers are susceptible to contrast effects in a multi-client environment. We demonstrate that auditors in the role of reviewers are also susceptible to contrast effects from a prior client. Audit reviewers' assessments of internal audit quality of a current client were significantly affected by the quality of the internal audit group of a client they previously reviewed. Specifically, when auditors first reviewed a client with a weak internal audit group they assessed the subsequent moderate internal audit group as being of higher quality than when they first reviewed a prior client with a strong internal audit group or did not review a prior client. Reviewers' documentation of evidence was also influenced by comparative information from the prior client. These results corroborate the key findings of Bhattacharjee et al. (2007) and confirm audit reviewers' susceptibility to contrast effects.


Author(s):  
Emily C. Whipple ◽  
Camille A. Favero ◽  
Neal F. Kassell

Abstract Introduction Intra-arterial (lA) delivery of therapeutic agents across the blood-brain barrier (BBB) is an evolving strategy which enables the distribution of high concentration therapeutics through a targeted vascular territory, while potentially limiting systemic toxicity. Studies have demonstrated lA methods to be safe and efficacious for a variety of therapeutics. However, further characterization of the clinical efficacy of lA therapy for the treatment of brain tumors and refinement of its potential applications are necessary. Methods We have reviewed the preclinical and clinical evidence supporting superselective intraarterial cerebral infusion (SSJACI) with BBB disruption for the treatment of brain tumors. In addition, we review ongoing clinical trials expanding the applicability and investigating the efficacy of lA therapy for the treatment of brain tumors. Results Trends in recent studies have embraced the use of SSIACI and less neurotoxic chemotherapies. The majority of trials continue to use mannitol as the preferred method of hyperosmolar BBB disruption. Recent preclinical and preliminary human investigations into the lA delivery of Bevacizumab have demonstrated its safety and efficacy as an anti-tumor agent both alone and in combination with chemotherapy. Conclusion lA drug delivery may significantly affect the way treatment are delivered to patients with brain tumors, and in particular GBM. With refinement and standardization of the techniques of lA drug delivery, improved drug selection and formulations, and the development of methods to minimize treatment-related neurological injury, lA therapy may offer significant benefits for the treatment of brain tumors.


2003 ◽  
Vol 14 (04) ◽  
pp. 202-212 ◽  
Author(s):  
Michael J. Cevette ◽  
Jürgen Vormann ◽  
Kay Franz

The last several decades have revealed clinical and experimental data regarding the importance of magnesium (Mg) in hearing. Increased susceptibility to noise damage, ototoxicity, and auditory hyperexcitibility are linked to states of Mg deficiency. Evidence for these processes has come slowly and direct effects have remained elusive because plasma Mg levels do not always correlate with its deficiency. Despite the major progress in the understanding of cochlear mechanical and auditory nerve function, the neurochemical and pharmacologic role of Mg is not clear. The putative mechanism suggests that Mg deficiency may contribute to a metabolic cellular cascade of events. Mg deficiency leads to an increased permeability of the calcium channel in the hair cells with a consequent over influx of calcium, an increased release of glutamate via exocytosis, and over stimulation of NMDA receptors on the auditory nerve. This paper provides a current overview of relevant Mg metabolism and deficiency and its influence on hearing.


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