35 research outputs found
Peculiarities of the volume magnetostriction in La₁₋xSrxMnO₃ in the Curie point region
The parallel λ∥ and perpendicular λ⊥ magnetostriction (with respect to the applied magnetic field) and the thermal expansion Δl/l are studied on La1−xSrxMnO₃ single crystals with x=0.1, 0.15, and 0.3. For the conducting sample with x=0.3 and the semiconducting sample with x=0.15 the volume magnetostriction (ω=λ∥+2λ⊥) is negative and the |ω|(T) curves go through a maximum at the Curie point TC. At T>TC its Δl/l temperature dependence is stronger than linear. For the semiconducting sample with x=0.1, ω is negative at T<TC and |ω|→0 at T∼TC. Its Δl/l is linear at T<=TC. The behavior of ω and Δl/l are explained by a magnetic two-phase state, due to strong s−d exchange
Measurements of spin rotation parameter A in pion-proton elastic scattering at 1.62 GeV/c
The ITEP-PNPI collaboration presents the results of the measurements of the
spin rotation parameter A in the elastic scattering of positive and negative
pions on protons at P_beam = 1.62 GeV/c. The setup included a
longitudinally-polarized proton target with superconductive magnet, multiwire
spark chambers and a carbon polarimeter with thick filter. Results are compared
to the predictions of partial wave analyses. The experiment was performed at
the ITEP proton synchrotron, Moscow.Comment: 7 pages, 3 figures. To be published in Phys. Lett.
Membranes with a boundary
We investigate the recently developed theory of multiple membranes. In
particular, we consider open membranes, i.e. the theory defined on a membrane
world volume with a boundary. We first restrict our attention to the gauge
sector of the theory. We obtain a boundary action from the Chern-Simons terms.
Secondly, we consider the addition of certain boundary terms to various
Chern-Simons theories coupled to matter. These terms ensure the full bulk plus
boundary action has the correct amount of supersymmetry. For the ABJM model,
this construction motivates the inclusion of a boundary quartic scalar
potential. The boundary dynamics obtained from our modified theory produce
Basu-Harvey type equations describing membranes ending on a fivebrane. The
ultimate goal of this work is to throw light on the theory of fivebranes using
the theory of open membranes.Comment: 48 pages, Latex, v2 references adde
First Measurement of A_N at sqrt(s)=200 GeV in Polarized Proton-Proton Elastic Scattering at RHIC
We report on the first measurement of the single spin analyzing power (A_N)
at sqrt(s)=200GeV, obtained by the pp2pp experiment using polarized proton
beams at the Relativistic Heavy Ion Collider (RHIC). Data points were measured
in the four momentum transfer t range 0.01 < |t| < 0.03 (GeV/c)^2. Our result,
averaged over the whole t-interval is about one standard deviation above the
calculation, which uses interference between electromagnetic spin-flip
amplitude and hadronic non-flip amplitude, the source of A_N. The difference
could be explained by an additional contribution of a hadronic spin-flip
amplitude to A_N.Comment: 13 pages, 5 figures. New values of polarization errors. Final version
submitted to Phys. Lett.
First Measurement of Proton-Proton Elastic Scattering at RHIC
The first result of the pp2pp experiment at RHIC on elastic scattering of
polarized protons at sqrt{s} = 200 GeV is reported here. The exponential slope
parameter b of the diffractive peak of the elastic cross section in the t range
0.010 <= |t| <= 0.019 (GeV/c)^2 was measured to be b = 16.3 +- 1.6 (stat.) +-
0.9 (syst.) (GeV/c)^{-2} .Comment: 9 pages 5 figure
LOW-TEMPERATURE TRANSITION METAL-SEMICONDUCTOR IN CdCr2Se4 SINGLE CRYSTALS DOPED WITH INDIUM AND GALLIUM
No abstract availabl
Background medical–geographical assessment of regions with high environmental tourism potential in the Republic of Kazakhstan
Influence of Oxigen Deficiency on Magnetic, Magnetoresistive and Magnetoelastic Properties of La<sub>1-x</sub>Sr<sub>x</sub>MnO<sub>3-y</sub> Manganites
Connection of thermopower and giant magnetothermopower with magnetic and structural heterogeneity in Sm0.55Sr0.45MnO3 manganite
Electrical and magnetic properties of La₁₋xAgyMnO₃ recrystallized ceramics
A method is presented to obtain silver-containing lanthanum manganites La₁₋xAgyMnO₃₊δ exhibiting GMR. Ceramic samples possessing high Curie temperature and showing a sharp maximum of metal-insulator transition near Curie temperature have been obtained.Представлен способ получения серебросодержащего манганита лантана, обладающего КМС. Получены керамические образцы, обладающие высокой температурой Кюри и проявляющие резкий максимум перехода металл-изолятор в области температуры Кюри.Представлено спосіб одержання срібловмісного манганіту лантану, що має КМС. Отримано керамічні зразки, які мають високу температуру Кюрі та виявляють різкий максимум переходу метал-ізолятор поблизу температур Кюрі