Ordering in the dilute weakly-anisotropic antiferromagnet Mn(0.35)Zn(0.65)F2

The highly diluted antiferromagnet Mn(0.35)Zn(0.65)F2 has been investigated by neutron scattering in zero field. The Bragg peaks observed below the Neel temperature TN (approximately 10.9 K) indicate stable antiferromagnetic long-range ordering at low temperature. The critical behavior is governed by random-exchange Ising model critical exponents (nu approximately 0.69 and gamma approximately 1.31), as reported for Mn(x)Zn(1-x)F2 with higher x and for the isostructural compound Fe(x)Zn(1-x)F2. However, in addition to the Bragg peaks, unusual scattering behavior appears for |q|>0 below a glassy temperature Tg approximately 7.0 K. The glassy region T<Tg corresponds to that of noticeable frequency dependence in earlier zero-field ac susceptibility measurements on this sample. These results indicate that long-range order coexists with short-range nonequilibrium clusters in this highly diluted magnet.Comment: 7 pages, 5 figure

Six pfennig (1693).

Coin reads: 6 PF: BRAN DENB LAND MUNTZ 1693. On the back is the Prussian coat of arms.Donated by Lew Franciszek de WR Chodkiewicz; Beer-Meyerbeer Family Collection.Jost Liebmann and his wife, Esther Schulhoff Liebmann, were Court Jews. Jost was the court jeweler of Elector Frederick III. of Brandenburg (King Frederick I. of Prussia), and one of the elders of the Jewish congregation of Berlin. As court Jew Jost succeeded Israel Aaron, and married his widow Esther in 1676. His wealth and standing at the court enabled him to exercise a great influence in the early period of the Jewish congregation. In 1684, they received permission to sponsor Berlin's sole synagogue, which functioned in their home. Among their numerous descendants are the brothers Giacomo Meyerbeer, Michael Beer, and Wilhelm Beer.Updated recordDigital imag

Oscillator strengths and radiative decay rates for spin-changing S-P transitions in helium: Finite nuclear mass effects

We have calculated the electric dipole (E1) and magnetic quadrupole (M2) oscillator strengths and spontaneous decay rates for 24 spin-changing transitions of atomic helium. We included the effects of the finite nuclear mass and the anomalous magnetic moment of the electron augmented by the recently derived Pachucki term. The specific transitions for 4He are and with and for For the E1 calculations we used the Breit approximation and pseudostate expansions to perform the perturbation sums over intermediate states in both the length and velocity gauge as a check on both numerical accuracy and validity of the transition operators. The corrections for the nuclear mass and the electron anomaly tend to cancel, indicating that if one is included, then so should be the other. The tables give mass- and anomaly-dependent coefficients permitting the easy generation of results for the other isotopes of helium.Peer reviewed: YesNRC publication: Ye