相关论文: Giant modification of atomic transitions probabili…
Pressure induced phase transitions of MIAgIIF3 perovskites where M = K, Rb, Cs, have been predicted theoretically for the first time for pressures up to 100 GPa. The sequence of phase transitions for M = K and Rb consists of an orthorhombic…
Accurate transition probabilities for forbidden lines are important diagnostic parameters for low-density astrophysical plasmas. In this paper we present experimental atomic data for forbidden [FeII] transitions that are observed as strong…
The features of Doppler-free resonances detected by probing the $^{133}$Cs atom $6S_{1/2}-7P_{3/2}$ transition at 456 nm in a nanometric-thick vapor layer are investigated. The matrix element of this transition is about 11 times smaller…
Based on the first-principles electronic structure calculations, we investigate the magnetic and electronic properties of transition-metal-doped Pb$_{10}$(PO$_4$)$_6$O with the Pb atom substituted by various transition metals. The $3d$…
Large magnetoresistive materials are of immense interest for a number of spintronic applications by developing high density magnetic memory devices, magnetic sensors and magnetic switches. Colossal magnetoresistance, for which resistivity…
A method for determination of atomic dipole matrix elements of principal transitions from the value of dispersion coefficient C_6 of molecular potentials correlating to two ground-state atoms is proposed. The method is illustrated on atomic…
Transport and magnetic studies of Ca3Ru2O7 for temperatures ranging from 0.4 K to 56 K and magnetic fields, B, up to 45 T leads to strikingly different behavior when the field is applied along the different crystal axes. A ferromagnetic…
Strain induced by a magnetic field is a common phenomenon for ferromagnets, but few antiferromagnets show large strain induced by a magnetic field. On the basis of linear strain measurements of sintered samples of triangular antiferromagnet…
While isovalent doping of GaAs (e.g. by In) leads to a repulsion between the solute atoms, two Cr, Mn, or Fe atoms in GaAs are found to have lower energy than the well-separated pair, and hence attract each other. The strong bonding…
A strong electronic reconstruction resulting in a quenching of the Fe magnetic moments has recently been predicted to be at the origin of the giant magnetocaloric effect displayed by Fe2Pbased materials. To verify this scenario, X-ray…
We report measurements of the absorption strength of the cesium $6s \: ^2S_{1/2} \rightarrow 7p \: ^2P_{3/2} $ and the $6s \: ^2S_{1/2} \rightarrow 7p \: ^2P_{1/2} $ transitions at $\lambda = 456$ nm and 459 nm, respectively, in an atomic…
We propose a new method to determine magnetic fields, by using the magnetic-field induced electric dipole transition $3p^43d\,^4\mathrm{D}_{7/2}$ $\rightarrow$ $3p^5\, ^2\mathrm{P}_{3/2}$ in Fe$^{9+}$ ions. This ion has a high abundance in…
It is now widely accepted that the magnetic transition in doped manganites that show large magnetoresistance is a type of percolation effect. This paper demonstrates that the transition should be viewed in the context of the Griffiths phase…
We show that the Second Derivative (SD) technique of the absorption spectra of Rb atomic vapours confined in a nanocell with a thickness $\ell= \lambda/2=398$ nm allows to achieve close to Doppler-free spectroscopy. Narrow linewidth and…
We investigate magnetic ordering in metallic Ba[Fe(1-x)Mn(x)](2)As(2) and discuss the unusual magnetic phase, which was recently discovered for Mn concentrations x > 10%. We argue that it can be understood as a Griffiths-type phase that…
An unusual successive phase transition from superconducting (SC) to antiferromagnetic (AF) phases was discovered via ^{75}As and ^{27}Al nuclear magnetic resonance (NMR) in (Fe_2As_2)(Ca_6(Al, Ti)_4O_y) with four (Al, Ti)O layers…
The magnetic properties of alkali-metal peroxychromate K$_2$NaCrO$_8$ are governed by the $S = 1/2$ pentavalent chromium cation, Cr$^{5+}$. Specific heat, magnetocalorimetry, ac magnetic susceptibility, torque magnetometry, and inelastic…
A combined experimental and theoretical study of transition matrix elements of the 6p 2Pj - 8s 2S1/2 transition in atomic Cs is reported. Measurements of the polarization-dependent two-photon excitation spectrum associated with the…
In this work, $\pi$, $\sigma^+$ and $\sigma^-$ transitions between magnetic sublevels of the $D_1$ line of all alkali atoms are considered analytically. General block Hamiltonian matrices in presence of a magnetic field for the ground and…
The electric dipole transition of the 3$^-$ state at 9.64 MeV of $^{12}$C to the 2$^+$ state at 4.44 MeV is speculated to play a key role in the triple-$\alpha$ reaction at high temperatures. A theoretical prediction of its transition width…