A Review of Thin-Film Magnetoelastic Materials for Magnetoelectric Applications.

Since the revival of multiferroic laminates with giant magnetoelectric (ME) coefficients, a variety of multifunctional ME devices, such as sensor, inductor, filter, antenna etc. have been developed. Magnetoelastic materials, which couple the magnetization and strain together, have recently attracted ever-increasing attention due to their key roles in ME applications. This review starts with a brief introduction to the early research efforts in the field of multiferroic materials and moves to the recent work on magnetoelectric coupling and their applications based on both bulk and thin-film materials. This is followed by sections summarizing historical works and solving the challenges specific to the fabrication and characterization of magnetoelastic materials with large magnetostriction constants. After presenting the magnetostrictive thin films and their static and dynamic properties, we review micro-electromechanical systems (MEMS) and bulk devices utilizing ME effect. Finally, some open questions and future application directions where the community could head for magnetoelastic materials will be discussed.

Carbon-based materials as adsorbent for antibiotics removal: Mechanisms and influencing factors.

With the development of the removal of organic pollutants in the soil and water environment, antibiotics have been considered as emerging pollutants and received considerable attention among the scientific community. Thus, there is a need for an effective, economical, fast, operational feasible and environmental-friendly technology to remove antibiotics. Adsorption technology would be one of the most promising option on the basis that it best meets the criteria we set out above. From the most primitive activated carbon to the most innovative modified biochar, carbon-based materials have played a significant role in the adsorption process of antibiotics all the time. This paper reviews the adsorption behavior of some representative antibiotics (e.g., chloramphenicols, sulfonamides, tetracyclines, flouroquinolones) over various carbonaceous materials (i.e., activated carbon, carbon nanotubes, graphene, and biochar). Nevertheless, in addition to the structural characteristics and adsorption capacities of carbon-based materials, a special emphasis was placed on the underlying adsorption mechanisms and roles of different influencing factors in the adsorption process. Moreover, the knowledge gaps and research challenges have been highlighted, including design and optimization of the carbonaceous materials for antibiotics adsorption.

Fabrication of sustainable manganese ferrite modified biochar from vinasse for enhanced adsorption of fluoroquinolone antibiotics: Effects and mechanisms.

An effective adsorbent towards fluoroquinolone antibiotics was synthesized via a facile two-step approach, the co-precipitation of Fe, Mn with vinasse wastes and then pyrolysis under controlled conditions which denoted as FMB. Its adsorption behavior was examined based on a batch adsorption experiment of fluoroquinolone antibiotics pefloxacin (PEF) and ciprofloxacin (CIP). Experimental factors, such as pH, adsorbent dose, ionic strength, contact time and temperature have done a great deal to influence the adsorption of PEF and CIP. The FMB demonstrated excellent performance in reusability tests towards to both PEF and CIP, which showed that the recycling efficiency of PEF and CIP could remain ~55% and ~80% after five recycle cycles, respectively. The dominated adsorption mechanisms included pore filling effect, π-π stacking interaction, π-π EDA, hydrogen bonding and hydrophobicity. Overall, this work presented FMB was recognized as an effective, environmental-friendly and magnetically separable adsorbent for alleviating fluoroquinolone antibiotics contamination from water.

A sustainable ferromanganese biochar adsorbent for effective levofloxacin removal from aqueous medium.

This present study reported the synthesis and characterization of a low-cost, environment friendly and high efficient biochar, ferromanganese modified biochar (Fe/Mn-BC) for the removal of levofloxacin (LEV) from aqueous medium. Fe/Mn-BC was synthesized through the facile co-precipitation of Fe, Mn with vinasse wastes and then pyrolysis under controlled conditions. The characterization of Fe/MnBC was analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction patterns (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman. Some influencing factors (e.g., pH, Fe/Mn-BC dosage, initial LEV concentration, ionic strength, contact time and temperature) were comprehensively investigated. The results manifested that the adsorption process of LEV onto Fe/Mn-BC was high pH dependence and the maximum adsorption capacity was achieved at pH 5. Moreover, the adsorption capacity of LEV was increased with increasing ionic strength. To gain a clearer perspective on the adsorption behavior of LEV onto Fe/Mn-BC, the adsorption kinetics and isotherms were also performed, revealing pseudo-second-order and Freundlich model had a better fitting effect. Reusability experiments indicated that Fe/Mn-BC could maintain a certain adsorption capacity for LEV after 5 recycles. Overall, this work showed that Fe/Mn-BC was an effective and promising adsorbent for eliminating LEV from aqueous medium.

Mechanical-Resonance-Enhanced Thin-Film Magnetoelectric Heterostructures for Magnetometers, Mechanical Antennas, Tunable RF Inductors, and Filters.

The strong strain-mediated magnetoelectric (ME) coupling found in thin-film ME heterostructures has attracted an ever-increasing interest and enables realization of a great number of integrated multiferroic devices, such as magnetometers, mechanical antennas, RF tunable inductors and filters. This paper first reviews the thin-film characterization techniques for both piezoelectric and magnetostrictive thin films, which are crucial in determining the strength of the ME coupling. After that, the most recent progress on various integrated multiferroic devices based on thin-film ME heterostructures are presented. In particular, rapid development of thin-film ME magnetometers has been seen over the past few years. These ultra-sensitive magnetometers exhibit extremely low limit of detection (sub-pT/Hz1/2) for low-frequency AC magnetic fields, making them potential candidates for applications of medical diagnostics. Other devices reviewed in this paper include acoustically actuated nanomechanical ME antennas with miniaturized size by 1-2 orders compared to the conventional antenna; integrated RF tunable inductors with a wide operation frequency range; integrated RF tunable bandpass filter with dual H- and E-field tunability. All these integrated multiferroic devices are compact, lightweight, power-efficient, and potentially integrable with current complementary metal oxide semiconductor (CMOS) technology, showing great promise for applications in future biomedical, wireless communication, and reconfigurable electronic systems.