Functionalized magnetic composite nano/ microfibres with highly oriented van der Waals CrI3 inclusions by electrospinning

This study reports on the synthesis of highly oriented chromium triiodide (CrI3) magnetic inclusions inside nano/microfibres with a polyethylene oxide matrix, prepared by the electrospinning technique. The structural, microstructural and spectroscopic analysis shows uniformly dispersed CrI3 nanosized inclusions inside the fibres, presenting a C2/m monoclinic structure at room temperature, where their c-axis is perpendicular to the fibre mat plane and the ab layers are in-plane. Analysis of the magnetic properties show that the samples have a ferromagnetic-paramagnetic phase transition at ∼55-56 K, lower than that of bulk CrI3. Noticeably, a field-driven metamagnetic transition is observed below ∼45 K, from M versus H curves, when the applied magnetic field is perpendicular to the fibre mat plane, while it is strongly reduced when the field is in-plane. This anisotropic behaviour is attributed to the field-induced changes from antiferromagnetic to ferromagnetic interlayer magnetic moment alignment along the CrI3 c-axis stacked layers. These CrI3 electrospun fibres then show an efficient cost-effective route to synthesize magnetic composite fibres with highly oriented van der Walls inclusions, for spintronic applications, taking advantage of their anisotropic 2D layered materials properties.We are grateful to the Fundacao Para a Ciencia e a Tecnologia (FCT) for the financial support through the Physics Centers of the Universities of Minho and Porto (Ref. UIDB/04650/2020) and projects UTAPEXPL/NTec/0046/2017, NORTE-01-0145-FEDER-028538 and PTDC/FIS-MAC/29454/2017. J H Belo thanks FCT for the Grant SFRH/BD/88440/2012, the project PTDC/FIS-MAC/31302/2017 and his contract DL57/2016 reference SFRH-BPD-87430/2012. J P Araujo and J H Belo thank the funding from the project, with reference POCI-01-0145-FEDER-032527. V B Isfahani acknowledges a Post-Doc grant from the project NORTE-01-0145-FEDER-028538. L Boddapati acknowledges the Nano TRAIN for Growth II program by the European Commission through the Horizon 2020 Marie Sklodowska-Curie COFUND Programme and support provided by the International Iberian Nanotechnology Laboratory. We are gratefull to Professor Michael Belsley, of the Physics Department at Minho University, for the fruitfull discussions on the manuscript

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved