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The intrinsic ferromagnetism of two-dimensional transition metal carbide Co2C is remarkable. However, its practical application in spintronic devices is encumbered by a low Curie temperature (TC). To surmount this constraint, double transition-metal carbide CoMC (M = Ti, V, Cr, Mn, Fe, Ni) monolayers are constructed with the aim of improving the magnetic properties and Curie temperature of Co2C. The magnetic properties of CoMC monolayers are comprehensively investigated by first-principles calculations and the effects of hole doping and biaxial strain on the magnetic properties of CoMC (M = V, Cr, Mn) monolayers are also studied. The ground states of CoTiC, CoMnC and CoNiC monolayers all favor ferromagnetic ordering, whereas the CoVC and CoCrC monolayers favor antiferromagnetic ordering and the CoFeC monolayer is non-magnetic. Excitedly, the CoMnC monolayer displays a high total magnetic moment of 4.024μB and a TC of 1366 K. Moreover, the control of hole doping can effectively improve the TC of CoVC, CoCrC, and CoMnC monolayers to 680, 1317, 3044 K, respectively. Finally, applying the in-plain biaxial strain, the CoVC monolayer can be transformed into a ferromagnetic semiconductor under a tensile strain of 6%. The TC values of CoVC, CoCrC, and CoMnC monolayers are tuned by biaxial strain to 440, 1334 and 2390 K, respectively. Their TC above room temperature demonstrates that these monolayers have potential applications in spintronic devices. These theoretical investigations provide valuable insights into guiding experimental synthesis endeavors. [ABSTRACT FROM AUTHOR]

Two-dimensional ferromagnets with a long-range ferromagnetic ordering at finite temperature present a bright prospect for their potential applications in nanoscale spintronic devices. The tuning of their intrinsic ferromagnetism and Curie temperature is essential for the development of next-generation data storage and spintronic devices. In this work, the electronic structures, ferromagnetism and Curie temperature of two-dimensional MnS2 monolayer are controlled by charge doping and electric field using first principles calculations. The results show that the dynamic and thermal stability of monolayer MnS2 for all of the cases can be still maintained. Moreover, there is no existence of phase transition and all MnS2 monolayers at any charge doping concentrations and electric field intensities favor ferromagnetic coupling. For the manipulation of electron doping, the calculated total magnetic moment Mtot of the MnS2 monolayer exhibits an increase from 3.112 to 3.491μB per unit cell. Further analysis indicates that a transition from half-metal to metal occurs by introducing the charge doping and vertical electric field, and the Mn 3d electronic states are the major determinants of ferromagnetism. Additionally, the charge doping enables the magnetic anisotropy energy to transform from an in-plane easy axis to the magnetization direction out of the plane. The Curie temperature Tc of the MnS2 monolayer can be moderately enhanced above room temperature by hole doping and application of a vertical electric field. Remarkably, Tc reaches its peak at 767 K at a hole doping concentration of −0.8e. This work enriches the microscopic understanding of the tuning mechanism of ferromagnetism and supplies a sound theoretical basis for subsequent experimental studies. [ABSTRACT FROM AUTHOR]

Oxidized Mg2Si films are annealed in low vacuum at various annealing temperature, and the degradation mechanism of Mg2Si during exploitation at high temperature is investigated. The crystal structure, surface morphology, depth profile, Raman scattering, and electrical properties are measured by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Hall effect system, respectively. XRD results show that MgO exists apparently in Mg2Si films, and as the annealing temperature increases, the content of MgO increases. The surfaces of films present distinct hexagon structures. The results of depth profiles show that the oxygen content decreases gradually from the surface to the subsurface. Raman spectroscopy analysis suggests that as the annealing temperature increases, the intensity of MgO peak enhances gradually. Hall measurement results indicate that the carrier concentration and mobility decrease significantly with the increase in annealing temperature. The films show n‐type at lower annealing temperature, while they present p‐type at higher annealing temperature, which indicates obvious conversions from n‐ to p‐type. [ABSTRACT FROM AUTHOR]

Heterostructured NiFe2O4/Ba0.85Ca0.15Ti0.9Zr0.1O3 (NFO/BCZT) composite thin films grown epitaxially on (100)-SrRuO3/SrTiO3 substrate (SrRuO3 is used as the bottom electrode) were prepared via pulse laser deposition. Phase formation of the tetragonal BCZT and cubic NFO were confirmed in X-ray diffractograms. A low RMS roughness and a smaller grain size were calculated from the surface microtopography. Physical properties testing indicated that such multiferroic heteroepitaxial composite thin films exhibit simultaneously excellent ferroelectric, dielectric, ferromagnetic properties, as well as conspicuous magnetoelectric effects. The saturated and remnant polarizations of NFO/BCZT film are about 35.79 and 12.43 μC cm−2 respectively, the magnetoelectric coupling coefficient reaches up to about 93 mV cm−1 Oe−1 at a bias magnetic field of 800 Oe, which is expected a bright application prospect in new storage technology and the medical field. [ABSTRACT FROM AUTHOR]

The near-infrared (NIR) long persistent phosphors have gained considerable attention owing to the potential applications in in vivo imaging. A novel NIR long-persistent phosphors Zn3Al2Ge3O12:Cr3+ was successfully synthesized by a high temperature solid-state reaction. The luminescent properties and the afterglow behaviors of the Zn3Al2Ge3O12:Cr3+ were investigated in detail. On the basis of thermoluminescence analyses, the mechanism of the persistent afterglow of the phosphors was also discussed briefly. The afterglow duration of this phosphor can last more than 12 h with the 650-750 nm emission range after stoppage of 254 nm ultraviolet light irradiation. Specifically, the persistent luminescence intensity and duration were regulated by changing Cr3+ doping concentration. All the results indicate that the Cr3+ activated Zn3Al2Ge3O12 has promising potential of practical applications. [ABSTRACT FROM AUTHOR]

Two-dimensional ferromagnets with a long-range ferromagnetic ordering at finite temperature present a bright prospect for their potential applications in nanoscale spintronic devices. The tuning of their intrinsic ferromagnetism and Curie temperature is essential for the development of next-generation data storage and spintronic devices. In this work, the electronic structures, ferromagnetism and Curie temperature of two-dimensional MnS 2 monolayer are controlled by charge doping and electric field using first principles calculations. The results show that the dynamic and thermal stability of monolayer MnS 2 for all of the cases can be still maintained. Moreover, there is no existence of phase transition and all MnS 2 monolayers at any charge doping concentrations and electric field intensities favor ferromagnetic coupling. For the manipulation of electron doping, the calculated total magnetic moment M tot of the MnS 2 monolayer exhibits an increase from 3.112 to 3.491 μ B per unit cell. Further analysis indicates that a transition from half-metal to metal occurs by introducing the charge doping and vertical electric field, and the Mn 3d electronic states are the major determinants of ferromagnetism. Additionally, the charge doping enables the magnetic anisotropy energy to transform from an in-plane easy axis to the magnetization direction out of the plane. The Curie temperature T c of the MnS 2 monolayer can be moderately enhanced above room temperature by hole doping and application of a vertical electric field. Remarkably, T c reaches its peak at 767 K at a hole doping concentration of -0.8 e . This work enriches the microscopic understanding of the tuning mechanism of ferromagnetism and supplies a sound theoretical basis for subsequent experimental studies.

RADA16-I (Ac-(RADA) 4 -CONH 2 ) is a widely investigated self-assembling peptide (SAP) in the biomedical field. It can undergo ordered self-assembly to form stable secondary structures, thereby further forming a nanofiber hydrogel. The modification of RADA16-I with functional peptide motifs has become a popular research topic. Researchers aim to exhibit particular biomedical signaling, and subsequently, further expand its applications. However, only a few fundamental reports are available on the influences of the peptide motifs on self-assembly mechanisms of designer functional RADA16-I SAPs. In this study, we designed RGD-modified RADA16-I SAPs with a series of net charges and amphiphilicities. The assembly/reassembly of these functionally designer SAPs was thoroughly studied using Raman spectroscopy, CD spectroscopy, and AFM. The nanofiber morphology and the secondary structure largely depended on the balance between the hydrophobic effects versus like-charge repulsions of the motifs, which should be to the focus in order to achieve a tailored nanostructure. Our study would contribute insight into considerations for sophisticated design of SAPs for biomedical applications.