peritecticadj.n.
/ˌpɛrᵻˈtɛktɪk/, U.S. /ˌpɛrəˈtɛktɪk/ Science.
A. adj.
Of, relating to, or designating a reaction that occurs between the solid phase and the liquid phase during the cooling of a mixture, with the formation of a new solid phase.
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the world > matter > chemistry > physical chemistry > phases > [adjective] > peritectic point
peritectic1924
peritectoid1936
1924 Z. Jeffries & R. S. Archer Sci. of Metals ix. 323 During the peritectic reaction there are three phases (two solid and one liquid) in equilibrium, so that the temperature must remain constant until at least one of the phases disappears.
1936 Nature 18 Apr. 657/2 Preliminary results from an X-ray study of the peritectic reaction α + liquid → β in the Cu-Zn system prove that the orientations assumed by the β-phase are definitely related to the orientation of the α-phase.
1967 A. H. Cottrell Introd. Metall. xv. 230 The silver-platinum system has a simple peritectic diagram.
1973 J. G. Tweeddale Materials Technol. I. vi. 163 The reverse type of change to a eutectic reaction called a peritectic reaction can occur in many materials.
2002 Jrnl. Petrol. 43 1694 Some orthopyroxene porphyroblasts may represent the residual peritectic product of a..melting reaction.
B. n.
1. A peritectic point or temperature.
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the world > matter > chemistry > physical chemistry > phases > [noun] > peritectic point
peritectic1929
peritectic point1955
1929 Jrnl. Iron & Steel Inst. 119 337 In carbon steels, between the temperature of freezing and that of the peritectic, iron containing a maximum of 0·07 per cent. of carbon is the only solid to separate.
1975 Nature 20 Nov. 220/2 Any model of the igneous processes which produced the eucrites must account for this preferential generation of liquids at peritectic A (Fig. 1).
1984 E. P. DeGarmo et al. Materials & Processes in Manuf. (ed. 6) v. 117 At 1495°C (2723°F), a peritectic occurs for alloys with low weight percent carbon.
1997 Jrnl. Alloys & Compounds 247 122 In such a diagram, the variation with temperature of the liquid corner of three phase tie-triangles appears as a series of univariant lines that intersect at eutectics and peritectics.
2. A mixture or alloy that has a peritectic point.
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1970 RCA Rev. 31 693 All of these materials are high-temperature peritectics.
1996 Jrnl. Alloys & Compounds 241 40 The quaternary RE compounds are capable of forming as peritectics with limited solid solutions.
2002 Geophysical Res. Lett. 29 45 The behaviour of the peritectic's melting curve above 0.5 GPa might play an important role in the evolution of a deep liquid layer in the interiors of the largest icy satellites including Titan, Ganymede and Callisto.
Compounds
peritectic point n. the state at which two solid phases and one liquid phase of a substance coexist in equilibrium, the composition being such that a fall in temperature results in the disappearance of the two phases that exist at higher temperatures; (also) the point representing this state in a constitutional diagram.
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the world > matter > chemistry > physical chemistry > phases > [noun] > peritectic point
peritectic1929
peritectic point1955
1955 Proc. Royal Soc. A. 233 202 Kofler's observations seem to confirm the presence of a true eutectic and peritectic point in the system.
2003 Jrnl. Crystal Growth 255 386 The two phases grew simultaneously below the peritectic temperature in the solution with the composition near the peritectic point.
peritectic temperature n. the temperature at the peritectic point.
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1924 Z. Jeffries & R. S. Archer Sci. of Metals ix. 323 There are different solid phases in equilibrium with the melt above and below the peritectic temperature.
1999 Jrnl. Amer. Ceramic Soc. 82 2551 BZN-based β-phase is an incongruent compound that dissociates to form α-phase and a liquid phase, with an absorption of heat, at its incongruent melting point (peritectic temperature) of 1100 degrees C.
Derivatives
periˈtectically adv. by a peritectic reaction.
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the world > matter > chemistry > physical chemistry > phases > [adverb] > peritectic point
peritectically1935
1935 G. E. Doan Princ. Physical Metall. iv. 158 At 1500° the melt and δ crystals react peritectically to form γ-iron solid-solution crystals.
1967 A. H. Cottrell Introd. Metall. xv. 233 Fig. 15.12 shows an example in which the γ primary solution also forms peritectically.
2003 Jrnl. Alloys & Compounds 349 105 The only genuine ternary phase, AuMnSb, has a very narrow composition range around Au35Mn30Sb35 and is stable up to 575±5 degrees C, where it decomposes peritectically.
This entry has been updated (OED Third Edition, December 2005; most recently modified version published online March 2022).
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adj.n.1924