Room-temperature zero thermal expansion in a cubic perovskite oxide SrCu3Fe4−xMnxO12

2015 ◽  
Vol 106 (15) ◽  
pp. 151901 ◽  
Author(s):  
Ikuya Yamada ◽  
Shohei Marukawa ◽  
Naoaki Hayashi ◽  
Masafumi Matsushita ◽  
Tetsuo Irifune
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Perovskite Oxide ◽  
Temperature Zero

Room Temperature Zero Thermal Expansion in a Cubic Cobaltite

2020 ◽  
Vol 11 (16) ◽  
pp. 6785-6790
Author(s):  
Zhijian Tan ◽  
Ping Miao ◽  
Masato Hagihala ◽  
Sanghyun Lee ◽  
Yoshihisa Ishikawa ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Temperature Zero

Equations of State for Natural and Synthetic Rubber-Like Materials. I Unaccelerated Natural Soft Rubber

1943 ◽  
Vol 16 (2) ◽  
pp. 297-309 ◽  
Author(s):  
R. L. Anthony ◽  
R. H. Caston ◽  
Eugene Guth
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Equations Of State ◽  
Intermolecular Forces ◽  
Theoretical Expression ◽  
Total Force ◽  
Inversion Point ◽  
Synthetic Rubber ◽  
First Approximation ◽  
Direct Contrast

Abstract Summarizing, the following important conclusions may be drawn from these experiments on a typical unaccelerated soft gum compound. 1. The existence of the inversion point in the stress-temperature curves is shown to be due solely to ordinary volume thermal expansion, and may be eliminated by correcting for this thermal expansion. 2. The curves given in Figure 8a show that, for compounds of this type, the change of entropy with elongation accounts for more than 90 per cent of the total stress at room temperature, while the internal-energy contribution is less than 10 per cent and, to a first approximation, may be neglected. In other words, the retractive force is due almost entirely to the tendency of the extended rubber molecules to return to a less ordered curled-up state. This is in direct contrast to the elasticity exhibited by ordinary bodies, in which case elasticity is due to intermolecular forces. 3. The contribution of the entropy force to the total force is well represented by the theoretical expression of James and Guth. This agreement constitutes our main reason for interpreting the entropy force as being due to the kinetic motion of the rubber molecules.

scholarly journals Substitutions of Zr4+/V5+ for Y3+/Mo6+ in Y2Mo3O12 for Less Hygroscopicity and Low Thermal Expansion Properties

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3945 ◽  
Author(s):  
Qiang Ma ◽  
Lulu Chen ◽  
Heng Qi ◽  
Qi Xu ◽  
Baohe Yuan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Crystal Structures ◽  
Room Temperature ◽  
Crystal Water ◽  
Thermal Expansion Property ◽  
Expansion Property ◽  
Low Thermal Expansion ◽  
Substitution Content ◽  
Structure And Microstructure

In this investigation, ZrxY2−xVxMo3−xO12 (0 ≤ x ≤ 1.4) is developed and the effects of the substitutions of Zr4+/V5+ for Y3+/Mo6+ in Y2Mo3O12 on the hygroscopicity and thermal expansion property are investigated. For the smaller substitution content (x ≤ 0.5), their crystal structures remain orthorhombic, while there is crystal water still in the lattice. The linear coefficients of thermal expansions (CTEs), for x = 0.1, 0.3, 0.5, and 0.7, are about −4.30 × 10−6, −0.97 × 10−6, 0.85 × 10−6, and 0.77 × 10−6 K−1, respectively, from 476 to 773 K, which means that the linear CTE could be changed linearly with the substitution content of Zr4+/V5+ for Y3+/Mo6+ in Y2Mo3O12. As long as the substitution content reaches x = 1.3/1.4, almost no hygroscopicity and low thermal expansion from room temperature are obtained and are discussed in relation to the crystal structure and microstructure.

The Effect of Thermal History on Porcelain Expansion Behavior

1989 ◽  
Vol 68 (9) ◽  
pp. 1313-1315 ◽  
Author(s):  
C.W. Fairhurst ◽  
D.T. Hashinger ◽  
S.W. Twiggs
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Heating Rate ◽  
Room Temperature ◽  
Heating Rates ◽  
Thermal Expansion Data ◽  
Temperature Range ◽  
Expansion Behavior

Porcelain-fused-to-metal restorations are fired several hundred degrees above the glass-transition temperature and cooled rapidly through the glass-transition temperature range. Thermal expansion data from room temperature to above the glass-transition temperature range are important for the thermal expansion of the porcelain to be matched to the alloy. The effect of heating rate during measurement of thermal expansion was determined for NBS SRM 710 glass and four commercial opaque and body porcelain products. Thermal expansion data were obtained at heating rates of from 3 to 30°C/min after the porcelain was cooled at the same rate. By use of the Moynihan equation (where Tg systematically increases in temperature with an increase in cooling/heating rate), the glass-transition temperatures (Tg) derived from these data were shown to be related to the heating rate.

Phase Transitions in Hoalga

1983 ◽  
Vol 21 ◽  
Author(s):  
M. Doukoure ◽  
D. Gignoux ◽  
F. Sayetat
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Magnetic Order ◽  
Magnetocrystalline Anisotropy ◽  
Exchange Interactions ◽  
Thermal Anomaly ◽  
Antiferromagnetic State ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Magnetic Structures

ABSTRACTHoAlGa is hexagonal at room temperature. It undergoes two magnetic transitions succesively at TN = 32 K from a paramagnetic to a triangular antiferromagnetic state where the Ho moments lie in the basal plane and at Tt = 18 K in the course of which the moments rotate toward c giving rise to a colinear antiferromagnetic arrangement. X-ray experiments performed between 5 and 300 K allow to determine the crystal evolution through the two transitions. The hexagonal symmetry is not lowered through the transitions; this result is compatible with the observed magnetic groups. The thermal expansion curves show a very anisotropic behaviour of the lattice parameters. The “c” parameter shrinks below TN and this anomaly is to be related to the magnetic order. Along a, a positive thermal anomaly appears below 70 K and this can be interpreted by crystal field effects. Stability of magnetic structures is discussed with regard to exchange interactions and magnetocrystalline anisotropy.

scholarly journals Metal–insulator-transition engineering by modulation tilt-control in perovskite nickelates for room temperature optical switching

2018 ◽  
Vol 115 (38) ◽  
pp. 9515-9520 ◽  
Author(s):  
Zhaoliang Liao ◽  
Nicolas Gauquelin ◽  
Robert J. Green ◽  
Knut Müller-Caspary ◽  
Ivan Lobato ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Switching ◽  
Room Temperature ◽  
Target Material ◽  
Insulator Transition ◽  
Fine Tuning ◽  
Perovskite Oxide ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Bond Angles

In transition metal perovskites ABO3, the physical properties are largely driven by the rotations of the BO6 octahedra, which can be tuned in thin films through strain and dimensionality control. However, both approaches have fundamental and practical limitations due to discrete and indirect variations in bond angles, bond lengths, and film symmetry by using commercially available substrates. Here, we introduce modulation tilt control as an approach to tune the ground state of perovskite oxide thin films by acting explicitly on the oxygen octahedra rotation modes—that is, directly on the bond angles. By intercalating the prototype SmNiO3 target material with a tilt-control layer, we cause the system to change the natural amplitude of a given rotation mode without affecting the interactions. In contrast to strain and dimensionality engineering, our method enables a continuous fine-tuning of the materials’ properties. This is achieved through two independent adjustable parameters: the nature of the tilt-control material (through its symmetry, elastic constants, and oxygen rotation angles), and the relative thicknesses of the target and tilt-control materials. As a result, a magnetic and electronic phase diagram can be obtained, normally only accessible by A-site element substitution, within the single SmNiO3 compound. With this unique approach, we successfully adjusted the metal–insulator transition (MIT) to room temperature to fulfill the desired conditions for optical switching applications.

Crystal Distortion Associated with Magnetic Ordering in Alpha Iron Oxide and Manganese Carbonate

1972 ◽  
Vol 16 ◽  
pp. 390-395 ◽  
Author(s):  
W. S. McCain ◽  
D. L. Albright
Keyword(s):  
Thermal Expansion ◽  
Lattice Constant ◽  
Room Temperature ◽  
Axial Ratio ◽  
Manganese Carbonate ◽  
Lattice Constants ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Position Parameter ◽  
Oxygen Distance

AbstractThe magnetic crystal disrortion of weakly ferromagnetic α-Fe2O3 was investigated by x-ray diffraction techniques. Here crystal distortion is taken as the temperature dependent changes of lattice constants and thermal expansion coefficients. Moreover, the oxygen position parameter and the carbon-oxygen distance of MnCO3 were determined.The lattice constants and thermal expansion coefficients of α-Fe2O3 were measured from room temperature down to 243°K. The crystal distortion, as measured by the changes in lattice constants, thermal expansion coefficients and axial ratio, was found to be highly anisotropic. The co hexagonal lattice constant was influenced very slightly by magnetic distortion; it changed only by 0.01 percent between room temperature and the Morin temperature of 254°K. On the other hand, the ao lattice constant changes by 0.11 percent between room temperature and the Morin temperature. The thermal expansion coefficients of the lattice constants showed a similar contrast. The co coefficient was found to be independent of temperature from room temperature down to the Morin temperature. However, in the same temperature range, the ao coefficient showed an anomalous increase with decreasing temperature. In addition, the ao coefficient showed an infinite discontinuity at the Morin temperature.The change in the axial ratio with temperature suggests that the net weak ferromagnetic moment of α-Fe2O3 reaches a maximum at 275°K.The oxygen position parameter, x, in MnCO3 as determined from two reflections has a value of 0.2702 ± 0.001. The carbon-oxygen distance as calculated from the lattice constants and the oxygen position parameter is 1.29 ±0.002 Å. This value is another confirmation of the Pauling theory of the resonating carbonate structure.

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