Role of exchange interaction in effecting spin-lattice relaxation: Interpretations of data onCr3+inCu2+xCr2xSn2−2xspinel and dangling bonds in amorphous silicon

1998 ◽  
Vol 58 (22) ◽  
pp. 14971-14977 ◽  
Author(s):  
Sushil K. Misra
Keyword(s):  
Amorphous Silicon ◽  
Exchange Interaction ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Dangling Bonds ◽  
Spin Lattice

scholarly journals The role of the glassy dynamics and thermal mixing in the dynamic nuclear polarization and relaxation mechanisms of pyruvic acid

2014 ◽  
Vol 16 (48) ◽  
pp. 27025-27036 ◽  
Author(s):  
M. Filibian ◽  
S. Colombo Serra ◽  
M. Moscardini ◽  
A. Rosso ◽  
F. Tedoldi ◽  
...  
Keyword(s):  
Relaxation Rate ◽  
Dynamic Nuclear Polarization ◽  
Pyruvic Acid ◽  
Nuclear Polarization ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Relaxation Rates ◽  
Thermal Mixing ◽  
Spin Lattice

In pyruvic acid containing 15 mM trityl below 4 K 13C polarization and spin–lattice relaxation rates are proportional to the spin–lattice relaxation rate of electrons, suggesting an efficient thermal mixing scenario.

Dipolar Measurements of Hydrogen in Amorphous Silicon

1992 ◽  
Vol 258 ◽  
Author(s):  
P. Hari ◽  
P.C. Taylor ◽  
R.A. Street
Keyword(s):  
Amorphous Silicon ◽  
Pulse Sequence ◽  
Lattice Relaxation ◽  
Dipolar Interaction ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Discharge System ◽  
Spin Lattice ◽  
Boron Doped ◽  
Foil Substrate

ABSTRACTThe dipolar interaction of hydrogen (∼ 10 at. %) in boron-doped amorphous silicon has been studied using the Jeener-Broekaert pulse sequence. The sample was prepared on an Al foil substrate at a temperature of 230°C using a standard glow discharge system (operating at 1 W rf power). The diborane/silane ration was 10-4. The same sample was removed from the Al substrate using dilute hydrochloric acid. The Jeener-Broekaert pulse sequence consists of three pulses: π/2|x′ – τ1 – π/4|y′ – τ2 – π/4|y′ – echo. We measured T1D, the dipolar spin lattice relaxation time, for τ1 = 82 μs, τ1 = 100 μs and τ1 = 50 μs at 299°K. The value of τ1D was found to be independent of τ1. At 335°K we found τ1D to be much longer than at room temperature. The values of τ1D at 299 K, 314 K and 335 K are, respectively, 0.7 ms, 1.2 ms and 1.8 ms. From the data we estimate an activation energy for microscopic motion to be ∼ 0.2 eV.

The role of the ordinary and anharmonic Raman processes in Rb2PtI6

1978 ◽  
Vol 56 (11) ◽  
pp. 1461-1467 ◽  
Author(s):  
Robert G. C. McElroy ◽  
Robin L. Armstrong
Keyword(s):  
Nuclear Spin ◽  
Lattice Relaxation ◽  
Experimental Results ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Raman Process ◽  
Nuclear Spin Lattice Relaxation ◽  
Rare Opportunity

Measurements of iodine nuclear spin lattice relaxation in Rb2PtI6 provide a rare opportunity to directly measure the separate contributions of the ordinary and anharmonic Raman processes. It is shown that for this crystal one may separately determine W1 and W2 and that these rates may be uniquely related to the two Raman processes. The experimental results show that the anharmonic Raman process is dominant but not to the total exclusion of the ordinary Raman process.

Change of Spin-Lattice Relaxation Time with Light Soaking for Defects in Hydrogenated Amorphous Silicon

1998 ◽  
Vol 37 (Part 1, No. 10) ◽  
pp. 5470-5473
Author(s):  
Wei-Chi Lai ◽  
Chun-Yen Chang ◽  
Meiso Yokoyama ◽  
Jen-Dar Guo ◽  
Jian-Shihn Tsang ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Hydrogenated Amorphous

Effects of Annealing Time and Temperature on Hydrogen in Doped and Intrinsic Amorphous Silicon

1991 ◽  
Vol 219 ◽  
Author(s):  
S. E. Ready ◽  
J. B. Boyce
Keyword(s):  
Amorphous Silicon ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Relaxation Times ◽  
Local Environment ◽  
Lattice Relaxation ◽  
Substantial Effect ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Long Time

ABSTRACTThe local environment and diffusion of hydrogen in hydrogenated amorphous silicon (a-Si:H) depend on both temperature and doping. Previous studies of hydrogen evolution indicate that the manner in which hydrogen diffuses and desorbs from the material depends on doping and may occur at relatively low temperatures over extended time frames. We have examined the microstructure of hydrogen in intrinsic, boron doped and phosphorous doped a-Si:H as a function of annealing temperature and annealing time using hydrogen NMR. Changes in both the H NMR spectrum and spin-lattice relaxation times occur. We find annealing time has only a small effect on these parameters, whereas the annealing temperature has a substantial effect. The bonded-H content drops and the molecular-H2 content is seen to decrease slightly as the samples are annealed to higher temperatures. However the bonded-H remains essentially constant for long time, low-temperature anneals, while the molecular-H2 content is also seen to diminish slightly. The changes are more profound for B-doped samples than for P-doped or intrinsic material, consistent with the conclusions of other studies.

scholarly journals Role of NH4 ions in successive phase transitions of perovskite type (NH4)2ZnX4 (X = Cl, Br) by 1H MAS NMR and 14N NMR

RSC Advances ◽  
2018 ◽  
Vol 8 (21) ◽  
pp. 11316-11323 ◽  
Author(s):  
Ae Ran Lim
Keyword(s):  
Phase Transitions ◽  
Chemical Shifts ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
1H Mas Nmr ◽  
Spin Lattice ◽  
Successive Phase ◽  
Perovskite Type

The 1H chemical shifts and the spin-lattice relaxation time, T1ρ, in the rotating frame of (NH4)2ZnX4 (X = Cl, Br) are observed in order to investigate local phenomena related to successive phase transitions.

Spin-lattice relaxation of spin pairs in CdSe:Mn by the Dzyaloshinski-Moriya exchange interaction

1992 ◽  
Vol 46 (17) ◽  
pp. 11216-11219 ◽  
Author(s):  
Xiaomei Wang ◽  
M. Dahl ◽  
D. Heiman ◽  
P. A. Wolff ◽  
P. Becla
Keyword(s):  
Exchange Interaction ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Spin Pairs
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