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The co-substitution effect of La and Fe ions on structural characterization, ferroelectric and magnetic properties, and energy storage efficiency of multiferroics Ba1-xLaxTi1-xFexO3 (0 ≤ x ≤ 0.20) was systematically studied utilizing a combination of x-ray diffraction, scanning electron microscopy, Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), ferroelectric, and magnetic measurements. The results show a structural transformation from the P4mm tetragonal phase to the Pm-3m cubic one at x = 0.04, with no hexagonal phase across the entire large doping range, which differs from the results previously reported for BaTiO3 systems doped solely with Fe. The XPS results show single valence states of Ba, La, and Ti ions, alongside a mixed valence state of Fe in the investigated samples. Magnetic measurements indicate that the pristine sample (x = 0) exhibits weak ferromagnetic (FM) phases within a diamagnetic (DM) matrix. At x < 0.10, the FM and DM phases are suppressed while the paramagnetic phase becomes dominant, indicating no interaction between Fe ions and a reduction in lattice intrinsic defects such as O and Ti vacancies. For 0.10 ≤ x ≤ 0.15, Fe ions start to couple with each other, enhancing the ferromagnetism. However, as x = 0.20, the saturation magnetization is significantly reduced, indicating competition between FM and antiferromagnetic interactions between Fe ions. Ferroelectric measurements demonstrate the ferroelectric nature of the lightly doped samples (x ≤ 0.10) and the lossy improper ferroelectric nature of the samples with 0.15 ≤ x ≤ 0.20. The lossy improper ferroelectricity is related to electron hopping between the Fe3+–Fe4+ interaction pathways. The coercive electric field, remnant polarization, and maximum polarization decrease with the increase of the porosity in the samples. Furthermore, Ba1-xLaxTi1-xFexO3 exhibits high energy storage efficiencies of up to ~ 77%. These findings demonstrate an effective way to make efficient energy storage materials through optimizing doping level and morphological properties in BaTiO3 and other ferroelectrics. [ABSTRACT FROM AUTHOR]

Sorting and trapping cells play an important role in fundamental cellular and biology research that enables the study of single-cell behaviors, which are different in comparison with a cluster of cells. Contactless handling techniques using different optical, mechanical, or magnetic phenomena have been studied for single-cell trapping. Among them, the diamagnetic force created by magnetic structures on cells is significant and stable both in time and in space. In this work, arrays of hard magnetic clusters in the PDMS background (hereafter called magnetic structure) were successfully fabricated using the magnetic imprinting method. The magnetic structure shows a proper magnetic property and the possibility to sort and trap T47D single cells via the diamagnetic levitation phenomenon at defined positions, which are both experimentally observed and theoretically calculated. The obtained results show the promise of developing a simple way to separate directly living cells. [ [ABSTRACT FROM AUTHOR]

Recently, two-dimensional (2D) layered organic-inorganic perovskites have been a hot topic not only in photovoltaics but also in optoelectronic applications due to their remarkable optical and electronic properties. In this study, the multiferroic property of the 2D layered (C6H5CH2CH2NH3)2NiCl4, abbreviated PEA-NiCl4, perovskite single crystals has been first reported. The crystals were synthesized by anti-solvent evaporation method by a layer-by-layer mode with relative smooth surface that confirmed by SEM image. The XRD patterns reveal the high crystalline quality with (n00) dominant plane (n = 2, 4, 6, …). The 180° reproducible hysteresis phase loop, butterfly-like amplitude curve, and an effective piezoelectric coefficient of 327 pm/V was evaluated using Piezoelectric Force Microscopy (PFM) measurement. The multiferroic properties has been confirmed by P-E hysteresis loops with PS = 16.3 µC/cm² Pr = 14.8 µC/cm², and EC = 6.7 kV/cm and M-H hysteresis loops with HC = 151 G. The 80-nm-width ferroelectric domains orienting along the crystal surface have been observed by the PFM images. This study offers an opportunity to develop new multiferroics material based on 2D layered hybrid perovskite single crystals. [ABSTRACT FROM AUTHOR]