Phenomenological analysis of α′_L-to-β martensitic transformation in phosphorus-bearing dicalcium silicate

Abstract

K. Fukuda: Phenomenological analysis of a 0 L -to-b martensitic transformation in phosphorus-bearing dicalcium silicate K. Fukuda: Phenomenological analysis of a 0 L -to-b martensitic transformation in phosphorus-bearing dicalcium silicate K. Fukuda: Phenomenological analysis of a 0 L -to-b martensitic transformation in phosphorus-bearing dicalcium silicate

The Effect of Heat Treatment on the Emission Color of P-Doped Ca2SiO4 Phosphor

“…The phase transition temperatures are, during the heating process, 963 K for β to α’ L , 1433 K for α’ L to α’ H , and 1698 K for α’ H to α. The β to α’ L phase transition of the cooling of doped C 2 S has been reported to be thermoelastic martensitic [9], hence the stabilized phases at ambient temperature systematically changed from β, β+α’ L to α’ L with increasing concentrations of foreign ions such as Sr 2+ , Ba 2+ , and/or P 5+ in C 2 S [10,11]. Thus, the change of crystal structures by heat treatment must be potentially able to improve the photoluminescence (PL) properties of the phosphors.…”

Morphology of α′H‐Ca2SiO4 Solid Solution Crystals

“…Taking into consideration the lattice correspondence between the α′ H and the β‐phases as (010) α′H ||(001) β and [001] α′H || [010] β , 12 the twinning must have occurred on (001) β . In a previous study, polysynthetic twinning on (100) β was occasionally recognized for the belite crystals that were quenched from the stable temperature region of the α‐phase 7,12 . On the other hand, the twinning on (001) β appeared only rarely 6 .…”

“…In a previous study, polysynthetic twinning on (100) b was occasionally recognized for the belite crystals that were quenched from the stable temperature region of the a-phase. 7,12 On the other hand, the twinning on (001) b appeared only rarely. 6 The (001) b twinning, as confirmed in the present belite, could preferentially occur when quenched from the stable temperature region of the a 0 H -phase.…”

“…This crystal had an orthorhombic unit cell of a, b , 3 c with the space group P 2 1 cn , where a, b , and c correspond to the unit cell of the α′ H ‐phase. The β‐phase is monoclinic; hence, the α′ L ‐to‐β‐phase transition is accompanied by the formation of polysynthetic twinning on either (100) β or (001) β 1,6,7 …”

“…The b-phase is monoclinic; hence, the a 0 L -to-b-phase transition is accompanied by the formation of polysynthetic twinning on either (100) b or (001) b . 1,6,7 The crystals of belite in industrial and/or laboratory cement clinkers normally show morphological instability during the solution growth process. 8,9 The a-phase crystals that were grown freely in a melt at high temperatures necessarily resulted in the rounded growth form.…”