Synthesis, tailoring the optical properties of insulating alkaline-earth metal oxide (MgO) with dopants of transition metal (Cu) and vibrating sample magnetometer measurements

Abstract

X-ray diffraction studies on MgO with copper dopants show the solubility limit of copper up to 3% preferably with f.c.c. (face centered cubic) structures. With doped of copper exceeding 3% in MgO. XRD showed phase changes with dopants of copper at 5% and exceeding 5% in MgO. Composites of two different crystalline phases are expected to appear (may be f.c.c cubic and f.c. triclinic). This confirmed to the fact that substitution or replacement of magnesium ions with copper ions would result into composite structures. Secondary phase appeared with exceeding 3% copper doping in MgO in the form of CuO as spherical nanoparticles and the same could be for MgO as spherical nanoparticles. EDX confirmed this behavior for copper dopants in MgO.With UV–visible absorption spectra, the quantum confinement effect is attributed to defects produced with dopants of copper ions as interstials in MgO within a limit of one to three percent. The observed size of MgO with SEM is 90.85 nm and the band gap is 4.68eV which are indicative of the transitions from insulating to dielectric behavior or to topological insulator.Experimental results of a.c. magnetic susceptibility with VSM on magnesium oxide and varying dopants of copper in MgO even with composite structures and phase changes show an antiferromagnetic behavior. This antiferromagnetic behavior is a manifestation of ‘topological insulator’ with enhanced dielectricity. Spin fluctuations due to nonlinear spin dynamics, triggered gyroscopic behavior in the nanomaterials, thereby producing quasiparticles of electrons and holes (vacant quantum states of electrons) as Majorana Fermions. Step transitions with upward and downward peaks of magnetization in MgO, with 3% copper ions concentrations and MgO with 8% copper ions concentration show ‘skyrmion like’ excitations with decreasing trends due to phase changes and composite structures but accompanied with negative slopes thereby maintaining ‘antiferromagnetic behavior’ as manifestations of topological insulators. Other samples of MgO with 1%, 5% and 10% copper ions concentrations showed antiferromagnetic behavior. With proper selection of copper dopants in MgO, various kinks of ‘spin fluctuations’ as manifestations of magnetic excitations can be produced to making these materials useful for diverse categories of devices.Mathematical result is proposed for eigenfunctions (shape profiles) and energy eigenvalues by considering the quasiparticles of energy fields for electrons and holes as Majorana Fermions with twisting and twigging in a braided configuration with QED behavior.