Electron Paramagnetic Resonance Investigation of the Ferroelectric Transition in N2H5Al(SO4)2·12H2O Crystals

Ching Jiun Wu, Jiang Tsu Yu

Research output: Contribution to journalArticle


The EPR spectra exhibited by the doped Cr3+ ions is sensitive to the reported low-temperature ferroelectric transition in N2H5Al(SO4)2·12H2O crystals. Structural informations that can be deduced from the experimental results include: (1) the appearance of merohedral twinning is concurrent with the onset of the structural phase transition; (2) the crystalline threefold symmetry, which is lost with the onset of the structural phase transition, becomes the twin law relating the orientations of the component domains; (3) the crystal symmetry below the transition temperature is orthorhombic; (4) the crystalline cubic axes of the high-temperature, cubic phase become the three crystalline twofold axes of the low-temperature, orthorhombic phase; and (5) a single Cr3+ species is detected in both the cubic and the orthorhombic phases, which implies that all the Al3+ sites are crystallographically equivalent in both phases.

Original languageEnglish
Pages (from-to)1688-1692
Number of pages5
JournalJournal of the Physical Society of Japan
Issue number6
Publication statusPublished - 1997 Jun



  • EPR
  • Structural phase transition

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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