Phase Transition and Thermal Expansion of Ba3RB3O9 (R = Sm-Yb, and Y)

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


High temperature powder X-ray diffraction measurements of Ba3RB3O9 (R=Sm-Yb, and Y) were carried out at temperatures ranging from room temperature to just below the corresponding melting temperatures (1,200-1,300 °C). No phase transition was found for the H-type phase (R3) with R=Sm-Tb and the L-type phase (P63 cm) with R=Tm-Yb. On the other hand, phase transition from the L phase to the H phase was observed for R=Dy-Er, and Y at around 1,100-1,200 °C. The obtained axial thermal expansion coefficient (ATEC) of the a-axis was larger than that of the c-axis for the H phase, and the ATEC of the c-axis was larger than that of the a-axis for the L phase. The observed anisotropic nature of ATEC is attributed to the distribution of the BO3 anionic group with rigid boron-oxygen bonding in the structures of the H and L phases.

Original languageEnglish
Pages (from-to)763-769
Number of pages7
JournalHigh Temperature Materials and Processes
Issue number8
Publication statusPublished - 2017 Sept 26


  • borates
  • high temperature
  • phase transition
  • thermal expansion
  • X-ray diffraction


Dive into the research topics of 'Phase Transition and Thermal Expansion of Ba3RB3O9 (R = Sm-Yb, and Y)'. Together they form a unique fingerprint.

Cite this