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In 3-3-1 models, anomaly cancellation requires that one of the three families of quarks transforms as triplet by SU 3 L , with the other two transforming necessarily as anti-triplet. This is an important feature of the model because, with it, we explain family replication. Thus it is mandatory to discriminate which of the families will transform as triplet by SU 3 L because the main consequence of anomaly cancellation in 3-3-1 models is the arising of processes violating flavor at the tree level by means of neutral currents mediated by gauge and scalar fields, and each case leads to different results. In this work, we consider the 3-3-1 model with right-handed neutrinos. Among the spectrum of 3-3-1 particles that contribute to the flavor changing neutral processes, there is a pseudoscalar that may be the lightest of the 3-3-1 particles, and this then should give the main contribution to such processes. We then calculate its contribution to the K 0 − K ¯ 0 mixing transition and confront it with the current experimental results. We do this for the three cases in which one of the family of quarks transforms as a triplet by SU 3 L . According to our findings, each case leads to different constraints on the mass of the pseudoscalar, and the case in which the third family of quarks transforms as triplet seems to be the favoured one. We also obtain the most stringent bounds on the mass of the pseudoscalar of the model. [ABSTRACT FROM AUTHOR]

We investigate the ionisation and fragmentation dynamics of free camphor molecules and camphor-doped helium nanodroplets by extreme ultraviolet (EUV) and soft x-ray photons using velocity map imaging combined with photoelectron-photoion coincidence (VMI-PEPICO) spectroscopy. We notably find that the Penning ionisation of camphor in He nanodroplets at h ν = 21.43 eV is soft with nearly identical Penning ionised electron spectra correlated to different molecular fragments. Further, fragmentation following ionisation at all photon energies exhibit a droplet-specific mass peak equivalent to the missing mass of CO, suggesting suppression of further fragmentation inside the droplet. This work reveals unusual features of photoionisation of organic molecules doped in He nanodroplet motivating further experimental and theoretical explorations. [ABSTRACT FROM AUTHOR]

Magnetic properties of indium oxide (In2O3) prepared by the decomposition of indium nitrate/indium hydroxide in the presence of ammonium chloride (NH4Cl) has been investigated. Structural and optical characterizations confirm that nitrogen is incorporated into In2O3. Magnetization has been convoluted to individual diamagnetic paramagnetic and ferromagnetic contributions with varying concentration of NH4Cl. Spin wave with diverging thermal exponent dominates in both field cool and zero field cool magnetizations. Uniaxial anisotropy plays an important role in magnetization as a function of magnetic field at higher concentration of NH4Cl. Avrami analysis indicates the absence of pinning effect in the magnetization process. Ferromagnetism has been interpreted in terms of local moments induced by anion dopant and strong hybridization with host cation. [ABSTRACT FROM AUTHOR]

Ferromagnetic BiFeO3 nanocrystals of average size 9 nm were used to form a composite with antiferromagnetic CuO nanosheets, with the composition (x)BiFeO3/(100−x)CuO, x = 0, 20, 40, 50, 60, 80 and 100. The dispersion of BiFeO3 nanocrystals into the CuO matrix was confirmed by x-ray diffraction and transmission electron microscopy. The ferromagnetic ordering as observed in pure BiFeO3 occurs mainly due to the reduction in the particle size as compared to the wavelength (62 nm) of the spiral modulated spin structure of the bulk BiFeO3. Surface spin disorder of BiFeO3 nanocrystals gives rise to an exponential behavior of magnetization with temperature. Strong magnetic exchange coupling between the BiFeO3 nanocrystal and the CuO matrix induces an interfacial superparamagnetic phase with a blocking temperature of about 80 K. Zero field and field cooled magnetizations are analyzed by a ferromagnetic core and disordered spin shell model. The temperature dependence of the calculated saturation magnetization exhibits three magnetic contributions in three temperature regimes. The BiFeO3/CuO nanocomposites reveal an exchange bias effect below 170 K. The maximum exchange bias field HEB is 1841 Oe for x = 50 at 5 K under field cooling of 50 kOe. The exchange bias coupling results in an increase of coercivity of 1934 Oe at 5 K. Blocked spins within an interfacial region give rise to a remarkable exchange bias effect in the nanocomposite due to strong magnetic exchange coupling between the BiFeO3 nanocrystals and the CuO nanosheets. [ABSTRACT FROM AUTHOR]

The ionization and fragmentation of two selenium containing hydrocarbon molecules, methylselenol (CH3SeH) and ethylselenol (C2H5SeH), by intense (>1017 W cm-2)5 fs x-ray pulses with photon energies of 1.7 and 2 keV has been studied by means of coincident ion momentum spectroscopy. Measuring charge states and ion kinetic energies, we find signatures of charge redistribution within the molecular environment. Furthermore, by analyzing fragment ion angular correlations, we can determine the laboratory-frame orientation of individual molecules and thus investigate the fragmentation dynamics in the molecular frame. This allows distinguishing protons originating from different molecular sites along with identifying the reaction channels that lead to their emission. [ABSTRACT FROM AUTHOR]

Flexible magnetoelectric 0–3 composite films formed with high dielectric (εr ∼ 104) CuO microparticles in a polyvinylidene fluoride (PVDF) polymer matrix showed multifunctional properties. The films prepared by the hot-moulding technique exhibit low-loss high relative permittivity (εeff ∼ 103) with good ferroelectric behaviour (with P–E loop) at the percolation threshold (fCuO = fc ∼ 0.25). Dielectric, ferroelectric, magnetic and direct magnetoelectric properties of the composites depend strongly on the CuO filler concentration (fCuO). Interesting low field magnetoelectric response appears with about 5% decrease in ferroelectric polarization in the insulating composite (fCuO = 0.20) along with 7.5% increase in the magnetodielectric coefficient under a magnetic field of 6 kG in the semiconducting percolative composite at room temperature. At this field, a maximum magnetoelectric voltage coefficient of 1.45 mV cm−1 Oe−1 was obtained. Even though the CuO sample is paramagnetic at ambient temperature, this typical composite film exhibits weakly ferromagnetic (with M–H loop) behaviour indicating multiferroic character. Our result represents an important step towards practical device applications using the high dielectric and magnetoelectric effects. [ABSTRACT FROM AUTHOR]

We report a simple technique for stabilization of a laser frequency at the wings of an atomic resonance. The reference signal used for stabilization issues from interference effects obtained in a low-quality cavity filled with a resonant atomic vapour. For a frequency detuned 2.6 GHz from the 133Cs D2 6S F = 4 to 6P F’ = 5 transition, the fractional frequency Allan deviation is 10−8 for averaging times of 300 s, corresponding to a frequency deviation of 4 MHz. Adequate choice of the atomic density and of the cell thickness allows locking the laser at detunings larger than 10 GHz. Such a simple technique does not require magnetic fields or signal modulation. [ABSTRACT FROM AUTHOR]

Magnetic interfaces created by the formation of a nanocomposite of ferromagnetic BiFeO3 nanoparticles of mean size 11 nm and antiferromagnetic network-like nanostructured NiO are studied. The effective radius of the ferromagnetic region is smaller than the actual nanoparticle size, thus confirming the involvement of a large fraction of surface spins in the interfacial magnetism. The exchange coupling between the BiFeO3 nanoparticles and the network-like nanostructured NiO leads to an interfacial blocking phase having an average blocking temperature of about 80 K. The temperature dependent saturation magnetization follows the Bloch law at high (150–300 K) temperature and exponential behaviour in intermediate (25–150 K) and low (5–25 K) temperature regimes. Exchange bias appears below the irreversible temperature of about 300 K, well below the Néel temperature of NiO. The composition dependences of the exchange bias field (HEB) and the coercivity (HC) reveal maximum values of HEB = 1550 Oe and HC = 1730 Oe at 5 K and a cooling field of 50 kOe for a BiFeO3 : NiO :: 50 : 50 concentration ratio. The exchange bias field decreases exponentially with increase of the temperature. Strong interfacial coupling due to uncompensated surface spins leads to a remarkable enhancement of the magnetic anisotropy at the BiFeO3/NiO interface. [ABSTRACT FROM AUTHOR]

Structural, optical, dielectric and ferroelectric properties of Ru-doped BaTi1−xRuxO3(x = 0.01, 0.03, 0.05, 0.07, 0.10) nanocubes have been investigated. The average size of nanocube obtained from Rietveld refinement is in the range 35–60 nm. The incorporation of Ru leads to a mixed tetragonal and cubic crystalline phases in doping concentration range 5–7%. Optical band gap changes from 3.2 to 2.74 eV with increase in Ru concentration. Replacement of Ti with Ru quenches band-edge emission and enhances defect emission intensity. Optical absorption and emission spectra have been interpreted in terms of oxygen vacancy. Ruthenium 4d orbital plays a crucial role to improve dielectric constant and diminish ferroelectric Curie temperature. The combined effect of Ru dopant and size gives rise to complex variation of Curie temperature. [ABSTRACT FROM AUTHOR]