Spin gap, phase separation and d-wave pairing as revealed by electron spin-lattice relaxation in 123 and 124 YBaCuO systems doped with Gd3+

2000 ◽  
Vol 19 (3-4) ◽  
pp. 329-337 ◽  
Author(s):  
V. A. Atsarkin ◽  
V. V. Demidov ◽  
G. A. Vasneva ◽  
G. Böttger ◽  
M. Gutmann
Keyword(s):  
Phase Separation ◽  
Electron Spin ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Gap ◽  
Spin Lattice ◽  
Wave Pairing ◽  
Gap Phase ◽  
D Wave

Effect of CuO Chains Ordering on the Opening of the Spin-Gap in YBa2Cu3O6+x

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1221-1227
Author(s):  
P. Carretta ◽  
P. Manca ◽  
S. Sanna
Keyword(s):  
Phase Separation ◽  
Hole Concentration ◽  
Nmr Relaxation ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Gap ◽  
Spin Lattice ◽  
Nuclear Spin Lattice Relaxation ◽  
Relaxation Measurements ◽  
Spin Excitations

The authors report on 63 Cu NMR relaxation measurements in YBa 2 Cu 3 O 6+x samples having similar T c's but a different structural ordering of the Cu(1)O chains. It is found that the gap in the spin excitations estimated from 63 Cu (2) nuclear spin-lattice relaxation rate 1/T1, varies from 110 K up to 190 K depending on the sample. This observation suggests that there is not a one to one relationship between the hole concentration and the amplitude of the spin-gap in the normal state of YBa 2 Cu 3 O 6+x. The sizeable variation in the gap, related to the different ordering of the Cu(1)O chains, is tentatively explained in the framework of a phase separation scenario where Cu(1)O chains act as pinning wells for the stripes.

Electron spin-lattice relaxation rate inY(Gd)Ba2Cu4O8:Evidence ford-wave pairing in high-Tcmaterials

2000 ◽  
Vol 61 (22) ◽  
pp. R14944-R14947 ◽  
Author(s):  
V. A. Atsarkin ◽  
V. V. Demidov ◽  
G. A. Vasneva ◽  
T. Fehér ◽  
A. Jánossy ◽  
...  
Keyword(s):  
Relaxation Rate ◽  
Electron Spin ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice Relaxation Rate ◽  
Spin Lattice ◽  
Wave Pairing ◽  
Lattice Relaxation Rate

Pulse Shaped Dynamic Nuclear Polarization Under Magic Angle Spinning

2019 ◽  
Author(s):  
ASIF EQUBAL ◽  
Kan Tagami ◽  
Songi Han
Keyword(s):  
Electron Spin ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Total Electron ◽  
Spin Lattice ◽  
Maximum Benefit ◽  
Selective Saturation ◽  
Angle Spinning

In this paper, we report on an entirely novel way of improving the MAS-DNP efficiency by shaped μw pulse train irradiation for fast and broad-banded (FAB) saturation of the electron spin resonance. FAB-DNP achieved with Arbitrary Wave Generated shaped μw pulse trains facilitates effective and selective saturation of a defined fraction of the total electron spins, and provides superior control over the DNP efficiency under MAS. Experimental and quantum-mechanics based numerically simulated results together demonstrate that FAB-DNP significantly outperforms CW-DNP when the EPR-line of PAs is broadened by conformational distribution and exchange coupling. We demonstrate that the maximum benefit of FAB DNP is achieved when the electron spin-lattice relaxation is fast relative to the MAS frequency, i.e. at higher temperatures and/or when employing metals as PAs. Calculations predict that under short T<sub>1e </sub>conditions AWG-DNP can achieve as much as ~4-fold greater enhancement compared to CW-DNP.

Sign in / Sign up

Export Citation Format

Share Document