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The past decade has seen a significant uptick in research interest to study the materials that can host magnetic skyrmion lattices. The curiosity of such materials is mainly driven by the technological applications of emergent skyrmion lattices that manifest a whirlpool-like spins arrangement. Insulating Cu _2 OSeO _3 reported to host magnetic skyrmion lattices below 60 K and considered as a potential candidate for exploring this new phase of materials. Here in this article, we propose a new synthesis process to grow the Cd ^2+ -substituted Cu _2 OSeO _3 nanocrystallites with variable sizes ranging over 50–200 nm. The proposed method consists of only a single-step heat treatment of 12 h, which is cost-effectivethan the routine solid-state process that requires a rigorous 15–20 days of heat treatment. By employing X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and isothermal magnetization (M-T) measurements, we present a comparative investigation of the structural, electronic and magnetic properties of pristine and Cd ^2+ -substituted Cu _2 OSeO _3 nanocrystallites. As non-magnetic substitution can alter the fundamental magnetic interactions, therefore, Cd ^2+ -Cu _2 OSeO _3 nanocrystallites offer a new methodology to control the magnetic skyrmion phases and its stability.

The first experimental evidence of Young-type interferences is presented in bremsstrahlung (BS) processes by measuring the double differential cross sections (DDCS) of BS photons emitted from a two-centre N2 molecule under impact of 4.0 keV electrons. The spectra were recorded for emission of photons in the angular range of 45°–120° and the energy range of 2.0–3.8 keV using a Si PIN photodiode detector (FWHM = 165 eV at 5.9 keV). The measured variation of DDCS ratio of N2 to Ar as a function of photon energy shows no obvious signature of interference structure. However, the measured angular distribution of the intensity ratio of BS photons of N2 to Ar is found to exhibit the noticeable oscillations. Furthermore, a clear oscillatory structure is observed in the angular distribution of BS photons if the intensity of photons emitted from N2 molecules at angle θ to the intensity of photons emitted at angle 90°, i.e. I(θ)/I(90°) is plotted as a function of emission angle. Noting the fact that, only one theoretical work on coherence effects in BS processes under low-energy electron impact with homonuclear diatomic molecules is reported in the literature by Borie et al (1970 Phys. Rev. A 2 1443) which fails to explain the observed oscillations and shows orders of magnitude difference in the amplitude and mismatch in the shape of oscillations. The presence of observed oscillations is suggested to arise due to coherent superposition of BS photons of a given energy emitted in scattering of 4.0 keV electrons with a two-centre N2 molecule. Strong disagreement between our measurements and the calculations from Borie et al theory clearly suggests that a more refined and adequate theoretical model together with additional experimental investigations are needed to verify the present observations. [ABSTRACT FROM AUTHOR]

Coincidences between energy selected electrons and ions produced in the decay of a core hole ionized (excited) state in a free nitrogen molecule have been measured at three specified energies of emitted electrons to reveal the individual pathways produced in 3.5 keV electron-induced fragmentation processes. From these measurements, it has been possible to show, for the first time, that in addition to the normal Auger decay, the resonant Auger excitation channels also share their appreciable contributions in producing singly charged parent ions in an electron-induced collision system. The correlations between ion fragmentation products and electronic structures with a hole configuration in singly-, doubly- and possibly in triply charged molecular electronic states populated in the electronic decay of the initial core hole have been studied and discussed. KER values obtained from our experiments are found to be consistent with the previous results of photo absorption experiments for fragmentation channel → N+ + N+; however, N2+ fragment ions are found to arise mainly from the fragmentation channel → N2+ + N and to possess relatively low kinetic energies in the considered region of binding energies. [ABSTRACT FROM AUTHOR]

An extensive analysis of individual high-multiplicity events produced in 208Pb-208Pb collisions is carried out by adopting different methods to examine the anomalous behavior of these rare events. A method of selecting the events with densely populated narrow regions or spikes out of a given sample of collision events is discussed. Employing this approach two events with large spikes in their η- and ϕ-distributions are selected for further analysis. For the sake of comparison, another two events which do not exhibit such spikes are simultaneously analyzed. The findings suggest that systematic studies of particle density fluctuations in one- and two-dimensional phase spaces and a comparison with those obtained from the studies of correlation-free Monte Carlo events, would be useful for identifying the events with large dynamical fluctuations. Formation of clusters or jet-like phenomena in multihadronic final states in individual events is also discussed and the experimental findings are compared with the independent particle emission hypothesis by carrying out Monte Carlo simulations. [ABSTRACT FROM AUTHOR]