Enhancement of uniaxial magnetic anisotropy in Fe thin films grown on GaAs(001) with an MgO underlayer

The understanding and control of anisotropy in Fe films grown on cubic systems such as GaAs and MgO has been of interest from the point of view of applications in devices. We report magnetic anisotropy studies on Fe/GaAs(001) and Fe/MgO/GaAs(001) prepared by pulsed laser deposition. In Fe/GaAs(001), magneto optical Kerr effect (MOKE) measurements revealed a dominant uniaxial anisotropy for Fe thickness less than 20 monolayers (ML) and this was confirmed by ferromagnetic resonance (FMR) studies. Multiple steps in the hysteresis loops were observed for Fe films of thickness 20 and 25 ML. Whereas, in Fe/MgO/GaAs(001), even at 25 ML of Fe, the uniaxial anisotropy remained dominant. The anisotropy constants obtained from FMR spectra have shown that the relative strength of uniaxial anisotropy is higher as compared to the cubic anisotropy constant in the case of Fe/MgO/GaAs(001). (C) 2011 American Institute of Physics. doi:10.1063/1.3556941]

Anisotropic low field magnetoimpedance in (001) oriented La0.7Sr0.3MnO3 thin films

We report the evidence for the anisotropic magnetoimpedance behavior in (001) oriented La0.7Sr0.3MnO3 (LSMO) thin films, in low frequency-low magnetic field regime. (001) oriented LSMO thin films were deposited using pulsed laser deposition and characterized with X-ray diffraction and temperature dependent magnetization studies. In the in-plain configuration, an ac magnetoresistance (MRac) of similar to -0.5% was observed at 1000 Oe, at 100 Hz frequency in these films. The MRac was found to decrease with increase in frequency. We observe increases in MRac at low frequency, indicating major contribution for change of permeability from domain wall motion. At higher frequencies, it decreases due to decrease in transverse permeability, resulting from dampening of domain wall motion. Out-of-plane configuration showed MRac similar to 5.5% at 1000 Oe, at 100 Hz frequency. The MRac turned from positive to negative with increase in frequency in out-of-plane configuration. These changes are attributed to the change in permeability of the film with the frequency and applied magnetic field.

BIMODAL NANOINDENTATION RESPONSE OF THE (001) FACE IN CRYSTALLINE SODIUM SACCHARIN DIHYDRATE

The nanoindentation response of the (001) face of sodium saccharin dihydrate is examined. The structure can be demarcated into regular and irregular regions or domains. The regular domains have solid-like and the irregular ones have liquid-like characteristics. Therefore, these domains impart a microstructure to the crystal. The indent face (001) is prominently developed in this crystal and unambiguously presents the regular and irregular regions to nanoindention. Average values of elastic modulus and hardness show a distinct bimodal mechanical response. Such a response has been observed in the case of intergrown polymorphs of aspirin and felodipine. We examine two possible reasons as to why the responses could be for bimodal in this crystal. The first possibility could be that the two domains correspond to regions of the original dihydrate and a lower hydrate that is obtained by the loss of some water. The second possibility could be that these responses correspond to regular and irregular regions in the structure. Nanoindentation is a very useful technique in the characterization of molecular solids, as a complementary technique to X-ray crystallography, because it samples different length scales.

Sapientia, 1969, Vol. XXIV, nº 93 (número completo)

Contenido: Verdad e historia / Octavio N. Derisi – Estructura de la obra de arte / Omar Argerami – En el bicentenario de un opúsculo kantiano / Manuel Trevijano – Amor y libertad en la filosofía de Gabriel Marcel / Carmen Valderrey – Notas y comentarios -- Bibliografía

Teología, 1969, Tomo VII nº 015-016 (número completo)

Presentación -- Asamblea extraordinaria del Sínodo de Obispos, octubre 1969 / Grupo de Obispos y expertos del CELAM -- Reflexión teológica sobre la realidad actual en Argentina / Eduardo F. Pironio -- Valor de los documentos de Medellín / Jorge Mejía -- Medellín: un caso de teología y pastoral / Eduardo Briancesco -- Medellín y el Ecumenismo / José Miguez Bonino -- Rol sacerdotal y cambio social / Francisco M. Suarez y Marta Mo Rigou -- Humanae Vitae, el magisterio episcopal y la conciencia /Rafael Braun -- La Escuela de Teología de la Universidad Católica de Mar del Plata / Oscar Amado -- Notas bibliográficas -- Libros recibidos -- Crónica de la Facultad -- Índice del Tomo VII (1969)

Sapientia, 1969, Vol. XXIV, nº 92 (número completo)

Contenido: El orden esencial y la inteligencia / Octavio N. Derisi – Las relaciones entre la ciencia y la filosofía / Juan A. Casaubón – Continuidad de la materia y participación / J. E. Bolzán -- Notas y comentarios -- Bibliografía

Teología, 1969, Tomo VII nº 014 (número completo)

“Humanae vitae” / J. F. Radrizzani -- Sentido evangélico del magisterio eclesiástico / Carmelo J. Giaquinta -- La “Humanae vitae” y su antropología / Juan F. Radrizzani -- El tema de la conciencia en los documentos recientes del magisterio / Rafael Braun -- Las declaraciones pastorales de los episcopados para la aplicación de “Humanae vitae” / Emilio Bianchi Di Carcano -- Licitud e ilicitud de las “píldoras” progestínicas después de la encíclica “Humanae vitae” / Rodolfo L. Nolasco -- Algunos aspectos de demografía mundial / Oscar H. Belaunde -- Una opinión protestante sobre “Humanae vitae” / José Miguez Bonino -- “Humanae vitae”: aporte para una bibliografía señalada de documentos y artículos con la colaboración de Héctor Agüer y Antonio Marino / Osvaldo D. Santagada -- Libros recibidos

Sapientia, 1969, Vol. XXIV, nº 91 (número completo)

Contenido: Contingencia y necesidad de las expresiones y usos materiales /Octavio N. Derisi – El sentido de la vigencia perenne del tomismo / Octavio N. Derisi – Idea y concepto en Spinoza y Santo Tomás / Augusto Furlán – Notas y comentarios -- Bibliografía

Diário da Constituinte [gravação de vídeo] : [programa n. 001]

Pronunciamento do Presidente da Assembleia Nacional Constituinte (ANC) Deputado Ulysses Guimarães para apresentar o funcionamento da ANC, inaugurar e anunciar o programa Diário da Constituinte como veículo de comunicação e disseminação dos trabalhos dos constituintes. No pronunciamento, o Presidente da ANC também convoca os brasileiros para participar da elaboração da futura constituição do país.

Flood of September 20-23, 1969 in the Gadsden County area, Florida

The center of low pressure of a tropical disturbance which moved northward in the Gulf of Mexico, reached land between Panama City and Port St. Joe, Florida, on September 20, 1969. This system was nearly stationary for 48 hours producing heavy rainfall in the Quincy-Havana area, 70-80 miles northeast of the center. Rainfall associated with the tropical disturbance exceeded 20 inches over a part of Gadsden County, Florida, during September 20 through 23, 1969, and the maximum rainfall of record occurred at Quincy with 10.87 inches during a 6-hour period on September 21. The 48-hour maximum of 17.71 inches exceeded the 1 in 100-year probability of 16 inches for a 7-day period. The previous maximum rainfall of record at Quincy (more than 12 inches) was on September 14-15, 1924. The characteristics of this historical storm were similar in path and effect to the September 1969 tropical disturbance. Peak runoff from a 1.4-square mile area near Midway, Florida, was 1,540 cfs (cubic feet per second) per square mile. A peak discharge of 45,600 cfs on September 22 at the gaging station on the Little River near Quincy exceeded the previous peak of 25,400 cfs which occurred on December 4, 1964. The peak discharge of 89,400 cfs at Ochlockonee River near Bloxham exceeded the April 1948 peak of 50,200 cfs, which was the previous maximum of record, by 1.8 times. Many flood-measurement sites had peak discharges in excess of that of a 50-year flood. Nearly $200,000 was spent on emergency repairs to roads. An additional $520,000 in contractual work was required to replace four bridges that were destroyed. Agricultural losses were estimated at $1,000,000. (44 page document)