In this paper, we investigate the coexistence between superconductivity and FERROMAGNETISM in a ferromagnetic superconductor (FS) where FS is in antiparallel cooper pairing state and parallel cooper pairing state. By using spin generalized Bogoliubov de Gennes (SBdG) equations, we derive the superconducting order parameter of FS as a function of temperature (T) and exchange field (h) of FS. We find that for some values of T and h the order parameter behaves as a multi-value function, so to determine the physical value of order parameter we calculate the difference in thermodynamic potential between superconducting and normal states, and we present a phase diagram of an FS in T-h plane which separates the superconducting region from the normal region. As a result, we deduce that the non-zero order parameter is not sufficient for having superconducting state and it is necessary to calculate the difference in thermodynamic potential of normal and superconducting states. In other word, in some points of T and h, although there are non-zero order parameters, since in these points the thermodynamic potential of the normal state is lower than the superconducting state, the system falls into the normal state.

Using the first-principles calculations, we have investigated the structural, electronic, and magnetic properties of the two-dimensional Janus MnSX (X= Cl, Br, I) monolayers. The dynamical stability for the 2D Janus monolayers has been confirmed by phonon spectrum calculation. Also, all manganese sulfide halide monolayers show half-metal with 100% spin polarization and a wide half-metallic gap. The noncollinear DFT calculations indicate that the two-dimensional Janus monolayers are ferromagnetically ordered systems and the preferred direction of magnetization lies in-plane of Janus manganese sulfide halide monolayers. The magnetic anisotropy energy increases from MnSCl to MnSI, related to the strong spin-orbit coupling at the I atom and the increased asymmetry between the sulfide and halide planes. The dispersion relation of magnetic excited states is obtained by applying the linear order Holstein–Primakoff transformation to the anisotropic Heisenberg Hamiltonian. We estimated Curie temperature for the monolayers by a self-consistent calculation of magnetization as a function of temperature. Our study presents a new class of 2D magnetic materials for future spintronics and valleytronics.

Diluted magnetic semiconductors (DMS) have received significant attention in the recent past in view of their significance for the rapidly developing field of spintronics. In this context, we have examined the case of Titanium oxide (TiO2) system dilutely (2 and 5 at %) doped with Manganese (Mn). These bulk polycrystalline samples exhibit rutile structure, which is the most stable structure amongst various configurations of TiO2. The Ti0.98Mn0.02O2 sample shows additional signatures of non-magnetic Mn2O3 in X-ray diffraction studies. Interestingly, Ti0.95Mn0.05O2 exhibits FERROMAGNETISM at very low temperature. X-ray diffraction studies show additional signatures of the Mn3O4 phase.Ion image and line scanning analysis of these samples using SIMS technique confirm that Mn atoms are not uniformly dispersed in the matrix and appear to have clustered. The nature of the clustered phase could be ascertained by magnetization measurements, which indicate a low temperature transition at 42 K, which is a characteristic of the Mn3O4 phase.

Using the transfer-matrix method, Spin transport in ferromagnetic bilayer graphene superlattice, which can be realized by putting a series of ferromagnetic insulator layers on top of a bilayer grapheme is studied. The ferromagnetic layers with exchange energy Eex are in contact with gate of potential energy V0. It is considered that the magnetization in the two ferromagnetic layers are aligned parallel (P) and antiparallel (AP) to each other. The spin transmissions probability (T­ and T¯) and the spin conductance (G­ and G¯) are studied. The spin polarization is calculated through the spin conductance. The total conductance (Gpq and GAPq) is also considered. It is found that perfect reflection can occur at normal incident, i.e., T­=T= 0. The spin conductance and the swpin polarization are found to exhibit oscillatory depending on the barrier height. The highest value of oscillating amplitude for SP% can rich 100% or (-100%) under special condition.

We give an overview of recent work on charge degrees of freedom of strongly correlated electrons on geometrically frustrated lattices. Special attention is paid to the checkerboard lattice, i.e., the two-dimensional version of a pyrochlore lattice and to the kagomé lattice. For the checkerboard lattice it is shown that at half filling when spin degrees of freedom are neglected and at quarter filling when they are included excitations with fractional charges ±e/2 may exist. The same holds true for the three-dimensional pyrochlore lattice. In the former case the fractional charges are confined. The origin of the weak, constant confining force is discussed and some similarities to quarks and to string theory are pointed out. For the checkerboard lattice a formulation in terms of a compact U(1) gauge theory is described. Furthermore a new kinetic mechanism for FERROMAGNETISM at special fillings of a kagomé lattice is discussed.

Multifunctional Zirconia Nanorods performing photocatalysis, anti-bacterial and anti-fungal activities are presented in this article. Tetragonal Zirconia is synthesized by the simple co-precipitation method. The synthesized Zirconia is characterized by various characterization methods such as XRD, SEM, EDX, UV-Vis, PL, VSM, and TG/DTA analysis. Exploration of powder XRD pattern indicates tetragonal phase. SEM image illustrates rod-shaped morphology. UV-Vis spectra reveal that the synthesized catalyst has a wide bandgap of about 4. 6eV. The emission peaks in the PL spectra reveal the presence of oxygen vacancies in the sample. Room Temperature FERROMAGNETISM (RTFM) is confirmed from VSM measurements. The performance of Zirconia nanorods in various applications such as photocatalysis, anti-bacterial and anti-fungal activities has been analyzed. t-ZrO2 photocatalyst degrades methylene blue dye with 80% removal efficiency in 180 minutes under UV light irradiation. t-ZrO2 obtained a 28mm inhibition zone against Staphaureus for anti-bacterial assessment while Amikacin has 15mm inhibition and obtained 25mm inhibition zone against Candida Albicans for anti-fungal assessment while Nystatin has 20mm inhibition. t-ZrO2 shows a superior inhibiting effect against both gram-positive and gram-negative bacterial pathogens. Owing to its high surface area it exhibits the greatest inhibiting effect against fungal strain.

In this paper, in order to investigation the effect of calcination temperature on the structural and magnetic properties of cobalt nanoparticles, samples have been prepared by Coprecipitation method at different calcination temperature. Cobalt nanoparticles have been prepared by Co-precipitation method at room temperature using hydrazine as reducing in ethanol hydrazine alkaline environment. This agent reduces cobalt salts to Cobalt nanoparticles in FCC and HCP phases. Phase analysis and investigation of Structural properties of the samples using X-ray diffraction patterns (XRD) confirm the formation of hexagonal phases of Co nanoparticles. Transmission electron microscopy (TEM) was used for determining the size and shape morphology of nanoparticles. Magnetic properties of these nanoparticles have been investigated using a Vibrating sample magnetometer (VSM). The results indicate that these nanoparticles are ferromagnetic at room temperature. In addition, in this paper Co nanoparticles coated with silica shell have been prepared by the wet chemical method. TEM images showed the cobalt core with average diameter of 17-20 nm coated by a silica shell with thickness of 5-7nm. Hysteresis Loop of these Co nanoparticles coated by silica shell illustrates 16.9 emu/gr for saturation magnetization at 10000 (Oe), which is much less than that of Cobalt nanoparticles.

We report the direct soft chemical synthesis and characterization of a family of face centered cubic (fcc) and partially ordered face centered tetragonal (fct) FePt nanoparticles (NPs) suitable for biomedical applications. Both fcc and partially ordered fct-FePt NPs are synthesized by employing a simple polyol method. By using polyvinyl pyrolidone (PVP) as a stabilizer in various ratios during synthesis, fcc-FePt NPs have been converted into partially ordered fct-FePt NPs at low temperature (300oC). The advantages of this process are its simplicity, the short reaction time, easy preparation and dispersibility of the NPs in aqueous media.

We present and compare the magnetic structures of limit compounds, between the FERROMAGNETISM and ant FERROMAGNETISM in the pseudobinary compounds of type RNi/Pt/Cu, where R = Tb, Gd, Nd or Ce, appearing when we substitute the transition metal. All of them are examples of complex magnetic structures as the result of different magnetic interactions, inhomogeneities and disorder. This overview provides us a fruitful field of discussion considering the competition of magnetic interactions in a context of disorder. We discuss the similarities and differences between the structures and we conclude about the importance of the disorder in the existence of several phenomena in magnetism, which could lead to new insights in the stability of magnetic phases, as clusters glass or short range interactions in the mesoscopic scale.