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51.
Graphical abstract
相似文献52.
53.
G. Srinivasan T.P. Mullin D. Hanna A. Manivannan M.S. Seehra 《Applied Physics A: Materials Science & Processing》2001,72(3):333-339
The nature of the double-exchange (DE) interaction in lanthanum manganites is studied through chemical substitutions, Cs for
La, and high-pressure measurements. Static and high-frequency magnetic measurements and high-pressure electrical transport
studies were carried out on bulk polycrystalline and radio-frequency sputtered thin films of La0.7-xCsxCa0.3MnO3 for x=0-0.1. The samples are found to be cubic. Curie temperature Tc measurements provide evidence for bond-length-related weakening of DE as x is increased from 0 to 0.03. For higher x, the
bond-angle-related changes lead to an increase in the strength of DE. High-pressure mangetoresistance data indicate both bond
length and bond-angle-related increase of 10–20 K/GPa in Tc with pressure, with the largest increase measured for x=0.03. The rate of increase in the Curie temperature with pressure
decreases with increasing Tc. Anomalies are observed in the magnetic parameters for x=0.03. The Cs-concentration dependence of the low-temperature saturation
magnetization shows a minimum close to x=0.03. Ferromagnetic resonance studies at x-band reveal a 5% decrease in the g-value
for x=0.03 relative to the end members (x=0 and 0.1). The low-field magnetostriction for x=0.03 indicates a relatively strong
electron–phonon spin coupling compared to neighboring compositions.
Received: 15 May 2000 / Accepted: 24 July 2000 / Published online: 9 November 2000 相似文献
54.
55.
The elastic constants of NaBrO3 and NaClO3 are evaluated from ultrasonic velocity measurements using pulse superposition techniques. The values of C11, C12 and C44 for NaBrO3 at 298°K are 5.578, 1.705, 1.510 (x 1010 N/m2) and for NaClO3 the values are 4.897, 1.389, 1.174. The values at 77°K are respectively 6.35, 1.98 and 1.65 for NaBrO3 and 6.15, 2.16 and 1.32 for NaClO3. 相似文献
56.
The irreducible representations of the group SO(4) in which the SO(3) subgroup is reduced are studied by an explicit construction of the operators and the basis in the spinor representation. The basis function which is formally identical with that for the coupling of two angular momentaj
1 andj
2 is expressible in terms of a hypergeometric function and strongly resembles the one for the irreducible representations of the groups SO(3,1). For the Lorentz group, the bases for the unitary representations which require unphysical values ofj
1 andj
2 are found to be analytic continuation of those for SO(4). The realization of the unitary irreducible representations of the group SO(4) in the Hilbert space of these functions leads, for appropriate unphysical values ofj
1,j
2, to the Gelfand-Naimark formula for the principal and complementary series of the representations of SO(3;1). The matrix elements for finite transformations of SO(4) and SO(3,1) can be evaluated, in this approach, in a unified manner by using standard properties of the hypergeometric function. These turn out to be a finite sum of3
F
2-functions which, as expected, are polynomials for SO(4) and infinite series for SO(3,1). A number of special matrix elements are calculated from the general formula and these agree with the results obtained previously.The authors are deeply indebted to Professor S.Dutta Majumdar fo many important suggestions and clarifications. 相似文献
57.
58.
Aryl/alkyl cyanides were quickly converted into the corresponding esters in the presence of iron(III) chloride in refluxing alcohols with very good yields. 相似文献
59.
Woldemedhin M. T. Srinivasan J. Kelly R. G. 《Journal of Solid State Electrochemistry》2021,25(10):2699-2700
Journal of Solid State Electrochemistry - 相似文献
60.
Ramajayam Govindan Mohamed El-Sherbiny Khalid Mohamed Morsy Ibraheem Srinivasan Narasimhan Mohamed EL-Dosoky Mohamed Salama Fazil Ahmad Selvaraj Jayaraman Vishnu Priya Veeraraghavan Srinivasan Vengadassalapathy Surapaneni Krishna Mohan Vidhya Rekha Umapathy Gayathri Rengasamy Shazia Fathima Jaffer Hussain Maheshkumar Poomarimuthu Senthilkumar Kalimuthu 《Molecules (Basel, Switzerland)》2022,27(3)