Search results for "Field dependence"
showing 10 items of 16 documents
AC Switching of Relaxor PLZT Ceramics
2005
The switching under application of bipolar ac field is studied by recording of the hysteresis loops in wide temperature and field range in PLZT x/65/35 ceramics. The qualitative difference of the shape of hysteresis loops above and below the freezing temperature is attributed to backswitching in relaxor phase due to the depolarization field produced by the bound charges located at the interphase boundaries. The application of the quasistatic approach to analysis of the experimental data allows us to obtain parameters of the distribution function of local coercive fields from the field dependence of the switching charge derivative on field.
Field dependence of spin and orbital moments of Fe in L10 FePt magnetic thin films
2006
Abstract The field dependence of spin and orbital magnetic moments of Fe in L10 FePt magnetic thin films was investigated using X-ray magnetic circular dichroism (XMCD). The spin and orbital moments were calculated using the sum rules; it was found that the spin and orbital moment of Fe in L10 FePt films are ∼2.5 and 0.2 μB, respectively. The relative XMCD asymmetry at Fe L3 peak on the dependence of applied field suggested that the majority magnetic moment of L10 FePt films resulted from Fe.
<title>Glass to ferroelectric phase transition induced by ac electric field in PbMg<formula><inf><roman>1/3</roman><…
2003
The nonlinear dielectric response of epitaxial heterostructures of relaxor ferroelectric PbMg1/3Nb2/3O3 thin films was experimentally studied using digital Fourier analysis. The amplitudes and the phase angles of the dielectric harmonics were determined as a function of temperature and the amplitude of the sinusoidal ac field. The response of the films was reconstructed assuming a linear contribution of the film-electrode interface capacitance. In the films at low amplitudes of ac field, a glass-like behavior was identified by a maximum in the third-order nonlinear dielectric permittivity around the freezing temperature, accompanied by a square field dependence of the amplitudes of the odd …
Precise vs General Feedback in Reducing Field-Dependence
1980
Summary.-To investigate the effect of feedback on performance of the Rod-and-frame Test the standard test procedure mas altered. The result of the alteration was a procedure which was called the Rod-and-frame Test as a Learning Task. On this task the subiect has to adjust the rod to the vertical twice in succession from each tilting position, whereby he is permitred a maximum of 10 trials in each tilting position and a range of tolerance of elo. After each trial the subject is given feedback about his performance. An experiment was conducted with 30 male and 30 female students to investigate whether a precise feedback giving both the direction and the degree of the rod's deviation from the …
A matter of perspective : the cognitive style Field Independence - dependence, and why it matters
2016
Psykologi Herman Witkin aloitti vuonna 1948 kognitiivista ajattelutapaa tutkivan suuntauksen, jossa ihmiset jaettiin kahteen ryhmään: kenttäriippuvaisiin ja kenttäriippumattomiin. Kenttäriippumattomuutta ja -riippuvaisuutta on tutkittu aina 2010 luvulle saakka. Kansainvälisiä tutkimustuloksia löytyy aiheeseen liittyen runsaastikin, mutta Suomessa aihetta ei ole juurikaan tutkittu soveltavan kielitieteen näkökulmasta. Tutkimukset kenttäriippuvaisuudesta ja -riippumattomuudesta antavat viitteitä siihen, että tällä kognitiivisen ajattelun mallilla saattaa olla suurikin vaikutus oppilaiden oppimismenestykseen. Kenttäriippumattomat oppilaat ovat aiempien tutkimusten mukaan itsenäisempiä, havaits…
Electromagnetic response of LaO_0.94F_0.06FeAs: AC susceptibility and microwave surface resistance
2009
We discuss on the electromagnetic response of a polycrystalline sample of LaO_0.94F_0.06FeAs exposed to DC magnetic fields up to 10 kOe. The low- and high-frequency responses have been investigated by measuring the AC susceptibility at 100 kHz and the microwave surface resistance at 9.6 GHz. At low as well as high DC magnetic fields, the susceptibility strongly depends on the amplitude of the AC driving field, highlighting enhanced nonlinear effects. The field dependence of the AC susceptibility exhibits a magnetic hysteresis that can be justified considering the intragrain-field-penetration effects on the intergrain critical current density. The microwave surface resistance exhibits a cloc…
A Dichoptic Edge Effect Resulting from Binocular Contour Dominance
1980
If one eye sees a bright field on a dark surround while a homogeneous background is presented to the other eye, then a distinct dark zone appears at the outer borders of the field.If the surround is coloured, then the zone is of corresponding hue. The effect disappears if the edge of the field can be fused with a bar of appropriate contrast. The influence of parameters such as pattern contrast and size were studied quantitatively. A model is proposed relating the effect to receptive-field organisation and the fusion process.
Sex Differences in Feedback: Effects on Rod-and-Frame Performance
1979
It has been demonstrated that feedback is effective in changing rod-and-frame performance for women if given the opportunity to adjust the rod to the vertical repeatedly from the same starting position. It is also shown that the significant difference between males and females in the Rod-and-frame Test is carried by the large difference in the initial tilting position.
Fluxon dynamics in Li–Al codoped by microwave surface resistance measurements
2010
Abstract The magnetic-field-induced variations of the microwave surface resistance, R s , have been investigated in ceramic Mg1−x(LiAl)xB2, with x in the range 0.1 – 0.4 . The measurements have been performed on increasing and decreasing the DC magnetic field, H 0 , at fixed temperatures. At low temperatures, we have observed a magnetic hysteresis in the R s ( H 0 ) curves in all the investigated samples. On increasing the temperature, the range of H 0 in which the hysteretic behavior is visible shrinks; however, in the sample with x = 0.1 it is present up to temperatures close to T c . We show that the field dependence of R s can be quantitatively justified taking into account the critical…
Structural and magnetic characterization of a 1D chain of [Co(II)2(mu-aqua)(mu-carboxylate)2] strung cores.
2009
A novel 1D chain built up from stringing of [Co2(μ-OH 2)(μ-O2CC(CH3)3)2] units with the bridging 2,2′-bipyrimidine ligand has been synthesized and structurally characterized. The chains are well isolated from each other by the bulky tert-butyl groups of the carboxlyates and show an alternating zigzag configuration for the Co(II) metallic centres. DC magnetic measurements show anti-ferromagnetic coupling, Jca.-3 cm-1 between adjacent Co(II) ions along the chain. Noticeably, good data fitting was obtained by means of simple models that neglect any kind of first order orbital contribution to the spin ground state, which is normally observed in Co(II) complexes. These results were further confi…