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X-ray absorption spectroscopy and photoemission electron microscopy are techniques commonly used to determine the magnetic properties of thin films, crystals, and heterostructures. Recently, these methods have been used in the study of magnetoelectrics and multiferroics. The analysis of such materials has been compromised by the presence of multiple order parameters and the lack of information on how to separate these coupled properties. In this work, we shed light on the manifestation of dichroism from ferroelectric polarization and atomic structure using photoemission electron microscopy and x-ray absorption spectroscopy. Linear dichroism arising from the ferroelectric order in the PbZr0:2Ti0:8O3 thin films was studied as a function of incident x-ray polarization and geometry to unambiguously determine the angular dependence of the ferroelectric contribution to the dichroism. These measurements allow us to examine the contribution of surface charges and ferroelectric polarization as potential mechanisms for linear dichroism. The x-ray linear dichroism from ferroelectric order revealed an angular dependence based on the angle between the ferroelectric polarization direction and the x-ray polarization axis, allowing a formula for linear dichroism in ferroelectric samples to be defined.

This study delineates the evolution of magnetic order in epitaxial films of the room-temperature multiferroic BiFeO3 system. Using angle- and temperature-dependent dichroic measurements and spectromicroscopy, we have observed that the antiferromagnetic order in the model multiferroic BiFeO3 evolves systematically as a function of thickness and strain. Lattice-mismatch-induced strain is found to break the easy-plane magnetic symmetry of the bulk and leads to an easy axis of magnetization which can be controlled through strain. Understanding the evolution of magnetic structure and how to manipulate the magnetism in this model multiferroic has significant implications for utilization of such magnetoelectric materials in future applications.

Experimental investigations of the magnetic dead layer in 7.6 nm thick film of La0.7Sr0.3MnO3 (LSMO) are reported. The dc magnetization (M) measurements for a sample cooled to T = 5 K in applied field H = 0 reveal the presence of negative remanent magnetization (NRM) in the M vs. H (magnetic field) measurements as well as in the M vs. T measurements in H = 50 Oe and 100 Oe. The M vs. T data in ZFC (zero-field-cooled) and FC (field-cooled) protocols are used to determine the blocking temperature TB in different H. Isothermal hysteresis loops at different T are used to determine the temperature dependence of saturation magnetization (MS), remanence (MR) and coercivity HC. The MS vs. T data are fit to the Bloch law, MS(T) = M0(1 – BT3/2), showing a good fit for T < 100 K and yielding the nearest-neighbor exchange constant J/kB ≅ 18 K. The variations of TB vs. H and HC vs. T are well described by the model often used for randomly oriented magnetic nanoparticles with magnetic domain diameter ≈ 9 nm present in the dead-layer of thickness d =1.4 nm. Finally, the data available from literature on the thickness (D) variation of Curie temperature (TC) and MS of LSMO films grown under 200, 150, and 0.38 mTorr pressures of O2 are analyzed in terms of the finite-size scaling, with MS vs. D data fit to MS(D) = MS(b)(1-d/D) yielding the dead layer thickness d = 1.1 nm, 1.4 nm and 2.4 nm respectively. Brief discussion on the significance of these results is presented. [ABSTRACT FROM AUTHOR]

Objectives: International guidelines and clearly defined care pathways on adult cochlear implantation (CI) are limited, and country-specific guidelines vary and are associated with disparate levels of access and systemic underuse across the world. In 2020, consensus statements were published representing the first step toward the development of international guidelines on best practices for CI in adults with severe to profound sensorineural hearing loss (SPNHL). The standard of care for adults with hearing loss should include treatments that best improve the individual's quality of life through optimizing hearing function, social participation, and engagement. For adults with SPNHL, the standard of care includes an accurate diagnosis and timely referral to an appropriate specialist centre for assessment and counselling. When it is indicated as the most beneficial treatment option, the patient should be advised by an appropriate healthcare professional about access to cochlear implantation (CI) and aftercare. Material and methods: An international group of CI users and experts in the fields of otology, audiology, and hearing care have been brought together to form a Task Force in partnership with the Cochlear Implant International Community of Action (CIICA). The aim of the Task Force is to develop living practice guidelines and guidance that can be adapted and adopted in country, in order to optimise the care for adults indicated for CI. Member affiliations will extend to national and international organisations and a wide range of stakeholders implementing hearing care solutions within the community and most importantly patient representatives with SPSNHL. Objective: The overall objective of the Task Force is to contribute to and support the effective development and subsequent dissemination and adoption into practice of a set of accurate, consistent, and usable guidance and guidelines. Results: As the guidance and guidelines will need to be updated as new evidence is published, the aim of the Task Force is therefore for continuity and evolution over the long-term. Developing a consistent approach to optimizing the care for hearing impaired adults who may not receive adequate benefit from hearing aids will help raise awareness and better de- fine referral and treatment pathways, so patients can receive information about a treatment option that may help them. [ABSTRACT FROM AUTHOR]