Thermal Expansion of (Sr[sub 1 – ][sub x]La[sub x])[sub 3]Ru[sub 2]O[sub 7] Single Crystals at Low Temperatures

2005 ◽  
Vol 47 (9) ◽  
pp. 1595
Author(s):  
N. V. Anshukova
1963 ◽  
Vol 7 ◽  
pp. 302-313
Author(s):  
William L. Baun ◽  
John J. Renton

AbstractSeveral special-purpose attachments have been designed and built for the Siemens horizontal diffractometer. Design details and experimental results are shown for the following equipment: (1) Low-temperature mount for poly crystalline materials—examples are shown illustrating identification of organic liquids crystallized at low temperatures, and results are presented on coefficient of thermal expansion of alloys in the binary system copper—platinum from −185 to 25°C. (2) Low-temperature mount for single-crystal studies—this design allows recording of higher-level layer lines by use of a domed beryllium window. Illustrations are shown for organic single crystals and for organic liquids crystallized in the lowtemperature mount. (3) Focusing attachment—this attachment uses a curved specimen mounted on the focusing circle (Seeman-Bohlin mounting). Comparisons of dispersion are made and examples such as the (400) reflection from molybdenum are shown using both curved and flat specimens. (4) Full-circle goniometer—this device has been used primarily for determining distribution of intensity in amorphous and semicrystalline polymers, but is applicable to study of single crystals. Examples of both of these applications are discussed.


1965 ◽  
Vol 43 (7) ◽  
pp. 1328-1333 ◽  
Author(s):  
D. A. Channing ◽  
S. Weintroub

The linear thermal expansion coefficients αψ of two single crystals of Zn of orientations ψ = 10.8° and 63.9 ° with the hexad axis were measured over the temperature range of about 20–270 °K using an absolute Fizeau optical interference technique. The two principal coefficients, [Formula: see text] and [Formula: see text], corresponding to ψ = 0° and 90 ° respectively, were calculated from the Voigt relation, and their values are compared with previously reported experimental data. Above 60 °K there is good agreement with previous work, and below 60 °K the results confirm, in general, the data obtained by McCammon and White. The Grüneisen parameter γ is essentially constant at about 2.1 in the range 100–270 °K, but below 100 °K γ rises appreciably with decreasing temperature and reaches the value of about 3.5 at 20 °K.


1978 ◽  
Vol 39 (C6) ◽  
pp. C6-406-C6-407 ◽  
Author(s):  
T. Fukase ◽  
T. Kobayashi ◽  
M. Isino ◽  
N. Toyota ◽  
Y. Muto

1972 ◽  
Vol 25 (7) ◽  
pp. 1411 ◽  
Author(s):  
LE Lyons ◽  
LJ Warren

The low-temperature fluorescence spectrum of purified vapour-grown anthracene single crystals is presented and the free-exciton emission distinguished from a number of defect or impurity bands present even in the purest crystals. In assigning the observed bands the symmetry of the active vibrations and the origin of background fluorescence and deformation bands are discussed. The phonon structure in the region of the fluorescence origin was found to be almost completely b-polarized. Emission of electronic origin (25103 cm-1) was too weak to be observed. Polarization ratios of the principal vibronio bands at 5.6 K are given.


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