Temperature Dependence of the Nuclear Quadrupole Resonance Frequency of 79Br in NaBrO3 and KBrO3

1968 ◽  
Vol 49 (5) ◽  
pp. 2464-2466 ◽  
Author(s):  
R. F. Tipsword ◽  
J. T. Allender ◽  
E. A. Stahl ◽  
C. D. Williams
Keyword(s):  
Resonance Frequency ◽  
Temperature Dependence ◽  
Nuclear Quadrupole Resonance ◽  
Nuclear Quadrupole Resonance Frequency ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

Temperature and pressure variation of the 35Cl nuclear quadrupole resonance frequency in K2IrCl6

1970 ◽  
Vol 48 (14) ◽  
pp. 1649-1656 ◽  
Author(s):  
Gregory L. Baker ◽  
Robin L. Armstrong
Keyword(s):  
Resonance Frequency ◽  
Temperature Dependence ◽  
Nuclear Quadrupole Resonance ◽  
Oscillation Frequency ◽  
Torsional Oscillation ◽  
Nuclear Quadrupole Resonance Frequency ◽  
Lattice Mode ◽  
Quadrupole Resonance ◽  
Temperature And Pressure ◽  
Nuclear Quadrupole

Experiments to study the temperature and pressure variations of the 35Cl nuclear quadrupole resonance (NQR) frequency in K2IrCl6 are described. The resonance frequency at atmospheric pressure is measured from 3.08 °K (the antiferromagnetic transition temperature) to 470 °K. Measurements of the pressure dependence of the resonance frequency for pressures to 5000 kg cm−2 have been carried out at five temperatures between 281 and 393 °K. A multiple-mode method is adapted to include the effect of the destruction of π bonding by the lattice vibrations and is then applied to the analysis of the temperature variation of the resonance frequency. The temperature dependence of the oscillation frequency of the rotary lattice mode is deduced. The behavior of the torsional oscillation frequency is nearly identical with that observed in K2PtCl6. An analysis of the combined results of the temperature and pressure studies in K2IrCl6 and similar results in K2PtCl6 suggest that volume effects as well as the destruction of π bonding may be important for the explanation of the experimental temperature dependence of the NQR frequency.

scholarly journals Nuclear Quadrupole Resonance Frequency in Multilayered Cuprates

2009 ◽  
Vol 78 (12) ◽  
pp. 123704 ◽  
Author(s):  
Michiyasu Mori ◽  
Navid Afzal Shooshtary ◽  
Takami Tohyama ◽  
Sadamichi Maekawa
Keyword(s):  
Resonance Frequency ◽  
Nuclear Quadrupole Resonance ◽  
Nuclear Quadrupole Resonance Frequency ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

Investigation of the Rotary Lattice Mode in R2PtCl6 Compounds. I. From Measurements of the 35Cl Nuclear Quadrupole Resonance Frequency

1971 ◽  
Vol 49 (19) ◽  
pp. 2381-2388 ◽  
Author(s):  
Douglas F. Cooke ◽  
Robin L. Armstrong
Keyword(s):  
Resonance Frequency ◽  
Nuclear Quadrupole Resonance ◽  
Atmospheric Pressure ◽  
Nuclear Quadrupole Resonance Frequency ◽  
Published Data ◽  
Lattice Mode ◽  
Quadrupole Resonance ◽  
Temperature And Pressure ◽  
Nuclear Quadrupole ◽  
Static Lattice

Measurements of the temperature and pressure variation of the 35Cl nuclear quadrupole resonance (NQR) frequency in Rb2PtCl6 and Cs2PtCl6 are reported. The resonance frequency is measured at atmospheric pressure for temperatures from 4 to 500 K and at four temperatures between 290 and 380 K for pressures to 5000 kg cm−2. Previously published data for K2PtCl6 are also included in the analysis. Static lattice NQR frequencies are deduced. The differences between the static lattice frequencies are compared with the calculations of Smith and Stoessiger. Thermal averaging of the electric field gradient at a chlorine site is assumed to be dominated by the Q3, Q4, Q5, and Q6 internal modes of the PtCl6 octahedra and by the rotary lattice mode. The rotary mode frequencies are deduced; they are of similar magnitude and increase in the same sequence as the frequencies deduced from infrared and Raman data. An analysis of the pressure dependence of the NQR frequencies leads to pressure coefficients for the rotary mode frequencies. The influence of the cage of R atoms surrounding a PtCl6 octahedron is shown to increase through the series K2PtCl6, Rb2PtCl6, Cs2PtCl6. Finally, a thermodynamic analysis of the NQR data is presented which shows the importance of taking specific volume effects into account.

A nuclear quadrupole resonance investigation of the effect of pressure on molecular rotation in K2PtCl6

1969 ◽  
Vol 47 (10) ◽  
pp. 1095-1100 ◽  
Author(s):  
R. L. Armstrong ◽  
K. R. Jeffrey
Keyword(s):  
Resonance Frequency ◽  
Nuclear Quadrupole Resonance ◽  
Activation Volume ◽  
Classical Model ◽  
Nuclear Quadrupole Resonance Frequency ◽  
Molecular Rotation ◽  
A Value ◽  
Quadrupole Resonance ◽  
Quadrupolar Relaxation ◽  
Nuclear Quadrupole

The pressure dependences of the 35Cl quadrupolar relaxation rate and nuclear quadrupole resonance frequency in K2PtCl6 are measured for hydrostatic pressures up to 5000 kg cm−2 at six temperatures. The temperatures were selected so that the effects of pressure on the rotation of PtCl6 groups could be investigated. The relaxation resulting from the molecular rotation is discussed in terms of the simple classical model of an activated process. An activation volume ΔV* = 25.6 cm3 mole−1 for the rotation is deduced. The effect of the onset of the rotation on the nuclear quadrupole resonance frequency is noted. The results are shown to be consistent with earlier measurements on the 14N resonance in (CH2)6N4. The activation energy ΔE* for the rotation is shown to have a value between 12.6 and 18.8 kcal mole−1.

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