Anomaly of Nuclear Quadrupole Relaxation in Cu2O Prepared at Low Temperatures

1986 ◽  
Vol 41 (1-2) ◽  
pp. 382-385 ◽  
Author(s):  
J. Kasprzak ◽  
J. Lus ◽  
J. Pietrzak
Keyword(s):  
Temperature Dependence ◽  
Cuprous Oxide ◽  
Thermal Processing ◽  
Low Temperatures ◽  
Room Temperature ◽  
Quadrupole Relaxation ◽  
Temperature Dependences ◽  
Powder Samples ◽  
Nuclear Quadrupole ◽  
Nuclear Quadrupole Relaxation

The 63Cu and 65Cu NQR transitions in powder samples of cuprous oxide have been investigated from 77 to 500 K and at room temperature after annealing up to 1100 K Significant differences in T1 , NQR linewidth Δv, and their temperature dependences were found among the samples prepared in different ways. For C u20 samples obtained in low temperatures (below 380 K), the temperature dependence of T1 below 380 K is o f activation character with Ea = 0.07 eV. These results are interpreted in terms of an electron hopping mechanism. Thermal processing of these samples permits to obtain irreversible electronic state and then the spectroscopic parameters are the same as for the samples obtained in high temperatures (above 1320 K).

81Br Nuclear Quadrupole Relaxation in Aluminium Tribromide

1995 ◽  
Vol 50 (8) ◽  
pp. 737-741 ◽  
Author(s):  
Noriaki Okubo ◽  
Mutsuo Igarashi ◽  
Ryozo Yoshizaki
Keyword(s):  
Room Temperature ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Quadrupole Relaxation ◽  
Spin Lattice ◽  
Raman Process ◽  
Nuclear Spin Lattice Relaxation ◽  
Nuclear Quadrupole ◽  
Nuclear Quadrupole Relaxation

Abstract The 81Br nuclear spin-lattice relaxation time in AlBr3 has been measured between 8 K and room temperature. The result is analyzed using the theory of the Raman process based on covalency. A Debye temperature of 67.6 K and covalency of 0.070 and 0.072 for terminal and 0.022 for bridging bonds are obtained. The correspondence of the latter values to those obtained from the NQR frequencies is low, in contrast to the previously examined compounds.

Temperature Dependence of the Nuclear Quadrupole Relaxation Rate in Silver and Sodium Halide Crystals

1995 ◽  
Vol 64 (2) ◽  
pp. 643-650 ◽  
Author(s):  
Toshihiro Yamanishi ◽  
Tatsuo Kanashiro ◽  
Yoshitaka Michihiro ◽  
Yutaka Kishimoto ◽  
Takashi Ohno
Keyword(s):  
Temperature Dependence ◽  
Relaxation Rate ◽  
Quadrupole Relaxation ◽  
Nuclear Quadrupole ◽  
Nuclear Quadrupole Relaxation

35Cl Nuclear Quadrupole Relaxation in Antimony Trichloride

1994 ◽  
Vol 49 (6) ◽  
pp. 680-686 ◽  
Author(s):  
Noriaki Okubo ◽  
Yoshihito Abe
Keyword(s):  
Low Temperatures ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Antimony Trichloride ◽  
Spin Lattice Relaxation ◽  
Quadrupole Relaxation ◽  
Spin Lattice ◽  
Raman Process ◽  
Nuclear Quadrupole ◽  
Nuclear Quadrupole Relaxation

Abstract The 35Cl NQR frequency and spin-lattice relaxation time in SbCl3 have been measured between 10 K and the melting point. The relaxation at low temperatures is attributed to the Raman process. A Debye temperature of 141 K and covalencies 0.390 and 0.356 are obtained. The latter values correspond well to those obtained from the NQR frequencies. For the relaxation above 200 K two more mechanisms are considered.

scholarly journals Effect of Mechanical Load on Defects Level in Soft Ferrite Ceramics

2018 ◽  
Vol 186 ◽  
pp. 02010
Author(s):  
A.B. Petrova ◽  
A.V. Malyshev ◽  
A.P. Surzhikov
Keyword(s):  
Temperature Dependence ◽  
Curie Point ◽  
Room Temperature ◽  
Mechanical Load ◽  
Initial Permeability ◽  
Temperature Dependences ◽  
Four Levels ◽  
Magnetic Ring ◽  
Soft Ferrite ◽  
With Screws

The article presents the results of a study of the effect of mechanical load on the temperature dependence of the initial permeability of LiTiZn soft ferrite ceramics. Regimes of mechanical load were created by a steel non-magnetic ring with screws. In this work, four levels of mechanical load were investigated: without load, with 1, 2 and 3 screws. For obtaining temperature dependences and exclude the influence of prehistory on the initial permeability, the samples were heated to a temperature exceeding the Curie point by 50 degrees, after which they slowly cooled to room temperature. The defects level was determined by the ratio of the parameters β / α of the phenomenological expression, which describes the experimental temperature dependences. It is shown that as the mechanical load increases, the defects level of ferrite ceramics increases, and after load removing, it returns to its original level.

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