977 resultados para TA R07 WELS
Resumo:
Sign.: A-Z8, 2A-2B8, 2C4
Resumo:
Lugar y fecha de imp. tomados del colofón en I8r
Resumo:
Dialecto : texto en euskera occidental -- vizcaíno, variedad occidental-arratia
Resumo:
Dialecto : texto en euskera occidental -- vizcaíno, variedad occidental
Resumo:
Dialecto : texto en euskera occidental -- vizcaíno
Resumo:
Capitulares grab. xil.
Resumo:
Dialecto : texto en euskera central -- guipuzcoano
Resumo:
Imp. tomados del colofón del t. 9
Resumo:
Pie de imp. tomado del colofón
Resumo:
In this work, the hyperfine quadrupole interaction at Ta-doped PbTi1-xHfxO3 polycrystalline samples is studied for the first time. Powders with x=0.25, 0.50 and 0.75 were prepared and characterized by X-ray diffraction analysis. Perturbed Angular Correlation (PAC) analyses were done as a function of temperature, using low concentration Ta-181 nuclei as probes. In the ferroelectric and paraelectric phases of these compounds two sites were occupied by the probes. For each site the quadrupole frequency, asymmetry and relative distribution width parameters were obtained as a function of temperature above and below the Curie temperature (T-C). One of these sites was assigned to the regular Ti-Hf site, while the other one was assigned to some kind of defect. The behavior of the hyperfine parameters as a function of temperature was analyzed in terms of a recent published phase diagram and the presence of disorder below and above T-C. For the three compositions measured, the obtained hyperfine parameters present discontinuities which correspond to the ferroelectric-paraelectric phase transition. In both phases it was found broad frequency distributed interactions. The disorder in the electronic distribution would be responsible for the broad line width of the hyperfine interaction. (C) 2012 Elsevier B.V. All rights reserved.