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The effect of the hydrostatic pressure on the electrical conductivity of silver iodide
Solid State Communications,
Vol. ii, pp. v—vu, 1972.
Pergamon Press.
Printed in Great Britain
Abstracts of Articles to be Published in The Journal of Physics and Chemistry of Solids ‘J Phys. Chem. Solids (to be published)’ should be cited in references to material quoted from this section prior to the publication of the relevant article. 1.
ABSORPTION SPECTRA AND 3~in CaF ZEEMAN EFFECTS OF Tm
with increasing temperature. These trends are 2
remarkably different from those in AgCI and AgBr. These results are discussed on the basis of the continuum model due to Keyes. It is pointed out that the effect of the thermal expansion coefficient may be important in order to interpret
Katsutoshi Muto, Central Research Laboratories, Mitsubishi Electric Corporation, Amagasaki, Japan.
the large change in the activation volume of yand ~-AgI.
3~in CaF The absorption spectra of Tm 2 were analyzed by the concentration series method at 3~ion 4.2°K. Systems of lines, belonging to Tm centers of different structure, are isolated from
Received 10 March 1972
the general spectra. Some structures of Tm3~ion centers were made clear by studying optical Zeeman effects and a change of absorption lines during thermal treatment. The tetragonal crystal field parameters and g-value of the upper state are also discussed.
CLASSICAL HEISENBERG FERROMAGNETS WITH DEFECTS V. Wildpanner, K. Binder and H. Rauch, Atominstitut der Osterreichischen Hochschulen, Vienna, Austria.
Received 10 March 1972 2.
A ferromagnetic (dimensionality d) containing defects (of dimensionality d’) is treated by the phenomenological Landau theory. It is shown
THE EFFECT OF THE HYDROSTATIC PRESSURE ON THE ELECTRICAL CONDUCTIVITY OF SILVER IODIDE
that for d’
.<
d
—
1 no change of the critical
exponent of the local magnetization near the defect occurs, in contrast to the case of the local magnetization near a surface (d’ = d — 1). The case of point defects (d’ = 0) in classical Heisenberg ferromagnets with nearest neighbor interactions is treated both by the mean field
Hideoki Hoshino and Mitsuo Shimoji, Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan.
approximation and the Monte Carlo method with The electrical conductivity of the ~)‘ and ~3-AgI pellets has been measured as a function of hydrostatic pressure up to 3300kg/cm2 in the temperature range between 10 and 100°C. The activation volumes determined from the data show a strong temperature dependence; in the ~ phase they are negative at 20°C and become more positive as the temperature rises, while in the ,3 phase they are negative and more negative
effective field boundary conditions. We obtain rough agreement between these two approaches — two special cases are considered in detail: (a) interaction with the defect being zero, (b) antiferromagnetic interactions across the defect (which is a crude model of superexchange). It is pointed out that it is a reasonable approximation to express the deviation of the local magnetization from the bulk value near the defect in terms of V
Vol. ii, pp. v—vu, 1972.
Pergamon Press.
Printed in Great Britain
Abstracts of Articles to be Published in The Journal of Physics and Chemistry of Solids ‘J Phys. Chem. Solids (to be published)’ should be cited in references to material quoted from this section prior to the publication of the relevant article. 1.
ABSORPTION SPECTRA AND 3~in CaF ZEEMAN EFFECTS OF Tm
with increasing temperature. These trends are 2
remarkably different from those in AgCI and AgBr. These results are discussed on the basis of the continuum model due to Keyes. It is pointed out that the effect of the thermal expansion coefficient may be important in order to interpret
Katsutoshi Muto, Central Research Laboratories, Mitsubishi Electric Corporation, Amagasaki, Japan.
the large change in the activation volume of yand ~-AgI.
3~in CaF The absorption spectra of Tm 2 were analyzed by the concentration series method at 3~ion 4.2°K. Systems of lines, belonging to Tm centers of different structure, are isolated from
Received 10 March 1972
the general spectra. Some structures of Tm3~ion centers were made clear by studying optical Zeeman effects and a change of absorption lines during thermal treatment. The tetragonal crystal field parameters and g-value of the upper state are also discussed.
CLASSICAL HEISENBERG FERROMAGNETS WITH DEFECTS V. Wildpanner, K. Binder and H. Rauch, Atominstitut der Osterreichischen Hochschulen, Vienna, Austria.
Received 10 March 1972 2.
A ferromagnetic (dimensionality d) containing defects (of dimensionality d’) is treated by the phenomenological Landau theory. It is shown
THE EFFECT OF THE HYDROSTATIC PRESSURE ON THE ELECTRICAL CONDUCTIVITY OF SILVER IODIDE
that for d’
.<
d
—
1 no change of the critical
exponent of the local magnetization near the defect occurs, in contrast to the case of the local magnetization near a surface (d’ = d — 1). The case of point defects (d’ = 0) in classical Heisenberg ferromagnets with nearest neighbor interactions is treated both by the mean field
Hideoki Hoshino and Mitsuo Shimoji, Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Japan.
approximation and the Monte Carlo method with The electrical conductivity of the ~)‘ and ~3-AgI pellets has been measured as a function of hydrostatic pressure up to 3300kg/cm2 in the temperature range between 10 and 100°C. The activation volumes determined from the data show a strong temperature dependence; in the ~ phase they are negative at 20°C and become more positive as the temperature rises, while in the ,3 phase they are negative and more negative
effective field boundary conditions. We obtain rough agreement between these two approaches — two special cases are considered in detail: (a) interaction with the defect being zero, (b) antiferromagnetic interactions across the defect (which is a crude model of superexchange). It is pointed out that it is a reasonable approximation to express the deviation of the local magnetization from the bulk value near the defect in terms of V