Measurement of spin–phonon transition probabilities in ruby

1970 ◽  
Vol 48 (9) ◽  
pp. 1099-1103 ◽  
Author(s):  
M. El-Azab ◽  
C. F. Weissfloch
Keyword(s):  
Transition Probabilities ◽  
Relaxation Times ◽  
Phase Method ◽  
Relaxation Processes ◽  
Spin Lattice ◽  
X Band ◽  
Coupling Parameters ◽  
Lattice Coupling ◽  
Phonon Transition ◽  
Spin Phonon Transition

Measurements at X-band frequencies of relaxation times and spin–phonon transition probabilities in ruby grown by the "vapor phase" method were carried out. They demonstrate the existence of relaxation processes which cannot be related to the spin–lattice coupling parameters obtained from ultrasonic and static stress experiments.

MEASUREMENT OF SPIN-PHONON TRANSITION PROBABILITIES IN POTASSIUM CHROMICYANIDE

1967 ◽  
Vol 45 (10) ◽  
pp. 3269-3273 ◽  
Author(s):  
C. F. Weissfloch
Keyword(s):  
Experimental Method ◽  
Transition Probabilities ◽  
Lattice Relaxation ◽  
Experimental Results ◽  
Spin Lattice Relaxation ◽  
Direct Process ◽  
Spin Lattice ◽  
Van Vleck ◽  
Phonon Transition ◽  
Spin Phonon Transition

An experimental method based on the technique of microwave pumping was used to measure spin-phonon transition probabilities in dilute potassium chromi-cyanide. The set of numerical values obtained appears to indicate that the spin-lattice relaxation by the direct process of the cyanide-coordinated Cr3+ ion violates the quadrupolar selection rules. This behavior is in disagreement with the Kronig – Van Vleck theory, but is not contradicted by the experimental results of other workers.

Solitons, polarons and their dynamics in mixed-valence halogen-bridged MX-chains

2007 ◽  
Vol 366 (1862) ◽  
pp. 93-100 ◽  
Author(s):  
Shinya Takaishi ◽  
Masahiro Yamashita
Keyword(s):  
Mixed Valence ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Relaxation Processes ◽  
Spin Lattice ◽  
H Nmr ◽  
Spin Resonance ◽  
1D Chain ◽  
The One

This article describes the photo-generation processes of elementary excitations such as solitons and polarons, and their dynamics in the one-dimensional (1D) halogen-bridged Pt compound [Pt(en) 2 Br](ClO 4 ) 2 . Spin-solitons were photo-generated via relaxation processes of CT excitons and self-trapped excitons, made evident by photo-induced absorption and photo-induced electron spin resonance spectra. Polarons were not generated from CT excitons. Diffusion of spin-solitons on the 1D chain was studied quantitatively by analysing 1 H NMR spin-lattice relaxation times ( T 1 ).

Nuclear Magnetic Resonance Studies of Molecular Motion in a Number of Stearates and Oleates

1971 ◽  
Vol 49 (5) ◽  
pp. 731-739 ◽  
Author(s):  
J. A. Ripmeester ◽  
B. A. Dunell
Keyword(s):  
Phase Transition ◽  
Alkali Metal ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Relaxation Mechanism ◽  
Spin Lattice Relaxation ◽  
Relaxation Processes ◽  
Lower Phase ◽  
Spin Lattice ◽  
Significant Difference

The broad line p.m.r. spectra of the alkali metal oleates have been observed from 77 °K up to or beyond the crystalline to waxy phase transition. Lower phase transition temperatures are observed in the oleates than in the stearates. This fact is attributed to larger entropies of transition in the oleates than in the stearates. The n.m.r. second moments indicate that in the stearates the packing of chains is probably not closer than in the oleates and consequently that the barriers to chain reorientation are not significantly higher in the stearates than in the oleates. Sodium oleate and stearate both appear to behave irregularly in the series of alkali metal soaps. Spin-lattice relaxation times have been measured by adiabatic rapid passage methods for both alkali metal oleates and stearates. Values of T1 and of the activation energy barrier for the reorientation of end methyl groups are compared with values obtained by other workers. No significant difference is seen between relaxation processes in stearates and oleates, at least in the lower temperature range. Soaps which seem to have some amorphous character have a second relaxation mechanism, in addition to end methyl group rotation, which is evidently important in the region of about 150–250 °K.

Spin–lattice relaxation of Fe3+ in rutile for X- and F-band transitions

1969 ◽  
Vol 47 (15) ◽  
pp. 1573-1583 ◽  
Author(s):  
G. J. Lichtenberger
Keyword(s):  
Relaxation Time ◽  
Temperature Dependence ◽  
Transition Probabilities ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Rate Equations ◽  
Relaxation Rates ◽  
Time Resolved ◽  
Spin Lattice

Detailed measurements of the angular and temperature dependence (1.6 °K to 4.2 °K) of the dominant spin–lattice relaxation rates of Fe3+ in rutile have been carried out for a number of strong transitions at 9.4 Gc and 121 Gc using the pulse saturation method. At 9.4 Gc, two relaxation time components were observed, ranging from 0.5 to 1.2 ms and 1.6 to 4.0 ms, respectively, at 4.2 °K. Assuming a relationship of the form log(relaxation time) = −n∙log(temperature), the temperature dependence factor n was found to be between 0.4 and 1.0. The single relaxation time resolved at F band had values from 0.7 to 1.0 ms at 4.2 °K, and n between 0.1 and 0.6. The corresponding relative relaxation rates were calculated from the direct process spin–phonon transition probabilities, assuming Debye elastic isotropy for rutile. Using a cubic spin–lattice coupling tensor, [Formula: see text] was found to be 0.5 and the rate equations for the six-level system were solved. The calculated effective relaxation times were successfully identified with the slower dominant relaxation component of the experimental data.

Electron–Phonon and Spin–Lattice Coupling in Atomically Thin Layers of MnBi2Te4

Nano Letters ◽  
2021 ◽  
Author(s):  
Jeongheon Choe ◽  
David Lujan ◽  
Martin Rodriguez-Vega ◽  
Zhipeng Ye ◽  
Aritz Leonardo ◽  
...  
Keyword(s):  
Thin Layers ◽  
Spin Lattice ◽  
Lattice Coupling

Relaxation processes of some simple aliphatic molecules in dilute solutions

1977 ◽  
Vol 55 (4) ◽  
pp. 297-301 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Carbon Tetrachloride ◽  
Dielectric Relaxation ◽  
Thermodynamic Parameters ◽  
Relaxation Times ◽  
Relaxation Processes ◽  
Dilute Solutions ◽  
Microwave Region ◽  
Nonpolar Solvents ◽  
Dielectric Data ◽  
Intramolecular Rotation

The dielectric relaxation processes of acetone, cyclohexanone, 4-methyl-2-pentanone, and 4-heptanone in dilute nonpolar solvents, n-heptane, cyclohexane, benzene, and carbon tetrachloride have been studied in the microwave region over a temperature range 10 to 60 °C. The relaxation times and the thermodynamic parameters for the activated states have been determined using the measured dielectric data. The results have been discussed in terms of dipole reorientation by molecular and intramolecular rotation and compared, wherever possible, with other similar studies on aliphatic molecules.

Spin-Lattice Coupling and Peculiarities of Magnetic Behavior of Ferrimagnetic Ludwigites Mn0.52+M1.52+Mn3+BO5(M=Cu, Ni)

2015 ◽  
Vol 233-234 ◽  
pp. 133-136 ◽  
Author(s):  
Leonard Bezmaternykh ◽  
Evgeniya Moshkina ◽  
Evgeniy Eremin ◽  
Maxim Molokeev ◽  
Nikita Volkov ◽  
...  
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Magnetic Anisotropy ◽  
Single Crystals ◽  
Magnetic Behavior ◽  
Temperature Hysteresis ◽  
Spin Lattice ◽  
Field Magnetization ◽  
Lattice Coupling

Temperature-field and orientational magnetization dependences of single crystals were measured. Both samples demonstrate significant field-depending temperature hysteresis and low-temperature counter field magnetization. The correlation of orientational dependences of these effects and magnetic anisotropy is analyzed; the role of spin-lattice interactions is discussed.

Relaxation processes of quinoline, isoquinoline, and their mixtures

1980 ◽  
Vol 58 (1) ◽  
pp. 20-24 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Thermodynamic Parameters ◽  
Molecular Motion ◽  
Polar Solvent ◽  
Relaxation Times ◽  
Relaxation Processes ◽  
Polar Components ◽  
Dielectric Absorption ◽  
System A ◽  
Dielectric Data ◽  
Activated State

The dielectric absorption of quinoline, isoquinoline, and their binary mixtures has been studied in the microwave region over a range of temperatures in dilute benzene and n-heptane solutions. The relaxation times and the thermodynamic parameters for the activated state have been determined using the measured dielectric data. The results obtained have been discussed in terms of the molecular motion of the system. A relation has been proposed to represent the relaxation behavior of a system of two Debye-type polar components in a non-polar solvent. The relation has been tested by comparing the calculated values with those determined experimentally for a few systems consisting of similar, simple rigid polar molecules.

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