Enhancement of critical Pr ion concentration (xcr) in (La1−xPrx)Ba2Cu3Oz

Abstract

The substitutional effect of Pr ion for La in (La 1Ϫx Pr x )Ba 2 Cu 3 O z bulk samples prepared under modified synthesis condition has been studied. Low field magnetization studies showed that superconductivity is retained up to the critical Pr ion concentration, x cr ϭ0.40. The effective magnetic moment of Pr 3ϩ free ion is very low in the present series of compounds. Results of X-ray absorption near-edge structure spectra for the series of (La 1Ϫx Pr x )Ba 2 Cu 3 O z compounds with 0.00ϽxϽ0.60 reveal that the doped Pr ion reduces hole concentration within the CuO 2 planes, leading to a destruction of superconductivity.

SUPERCONDUCTING PROPERTIES AND ORIENTATION BEHAVIOR OF REBa2Cu3Oy (RE = Yb, Er, Sm, Nd and La) FILMS BY METAL-ORGANIC DEPOSITION

“…Possible reason for this result might be reduction of superconducting carrier by RE/Ba substitution and oxygen deficient. [4][5][6] As shown in Fig. 8 covered with well-grown grains with many cracks.…”

Electronic and local atomic structures of (La1−xPrx)0.85Zr0.15MnO3studied by x-ray absorption spectroscopy

“…Any variation in O 2p-Mn 3d hybridization is believed to affect electronic states near the Fermi level. The additional features at the lower energy side of feature B 3 may originate from O 2p-Pr 5d/Zr 4d hybridized orbitals [23]. The minor changes in feature C 3 as the Pr content increases can be attributed to the slight distortion of the local structure caused by the substitution of La ions with a covalent radius of 1.160 Å by smaller Pr ions with a covalent radius of 1.126 Å for Pr 3+ and 0.960 Å for Pr 4+ [23].…”

The Influence of Zn<sup>2+</sup> Ions Substitution on the Microstructure and Transport Properties of Mn-Zn Nanoferrites

“…The increase of the activation energy from order to disorder state was attributed to the volume expansion above T c . The lower activation energy in the ferrimagnetic region is attributed to the magnetic spin disordering due to decrease in the concentration of current carriers [25] [26], while the change in activation energy is attributed to the change in conduction mechanism (polaron hopping). This decrease of resistivity in ferrite is due to the exponential increase of drift mobility of charge carriers with temperature.…”