Dimorphism in methylammonium aluminum alum studied by X-ray diffraction and electron paramagnetic resonance

Ssu Hao Lou, Jiang-Tsu Yu

Research output: Contribution to journalArticle

Abstract

We have found a reliable method of growing single-phase methyl-ammonium alum (MASD) crystallising in the infrequently-occurring α alum structure; the presence of the perchlorate ion, ClO4 -, in growth solutions induces the crystallisation of α MASD crystals. Seeding the growth solution with α MASD crystals also induces crystallisation of new α MASD crystals. The X-ray powder diffraction pattern and the EPR spectrum of the Cr3+ ions doped into α MASD are drastically different from those for the more frequently occuring β MASD. The linewidths of Cr3+ in α and β MASD show anomalous angular dependence. The inhomogeneous line broadening observed for β MASD could be explained by a random distribution in the orientation of the symmetry axis of the trigonal [Cr(H2O)6]3+ complex. The linewidth anomaly shows a more complicated angular dependence for α MASD; it could be that not only the orientation of the symmetry axis but also the magnitude of the axial crystal field of [Cr(H2O)6]3+ suffer random distributions.

Original languageEnglish
Pages (from-to)775-779
Number of pages5
JournalSolid State Communications
Volume84
Issue number7
DOIs
Publication statusPublished - 1992 Jan 1

Fingerprint

alum
Aluminum
Paramagnetic resonance
electron paramagnetic resonance
statistical distributions
aluminum
X ray diffraction
Crystals
Crystallization
diffraction
Linewidth
crystallization
crystals
x rays
symmetry
inoculation
perchlorates
crystal field theory
Ions
ions

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Materials Chemistry

Cite this

Dimorphism in methylammonium aluminum alum studied by X-ray diffraction and electron paramagnetic resonance. / Lou, Ssu Hao; Yu, Jiang-Tsu.

In: Solid State Communications, Vol. 84, No. 7, 01.01.1992, p. 775-779.

Research output: Contribution to journalArticle

@article{168c17931277483cbeb22cde11345ee8,
title = "Dimorphism in methylammonium aluminum alum studied by X-ray diffraction and electron paramagnetic resonance",
abstract = "We have found a reliable method of growing single-phase methyl-ammonium alum (MASD) crystallising in the infrequently-occurring α alum structure; the presence of the perchlorate ion, ClO4 -, in growth solutions induces the crystallisation of α MASD crystals. Seeding the growth solution with α MASD crystals also induces crystallisation of new α MASD crystals. The X-ray powder diffraction pattern and the EPR spectrum of the Cr3+ ions doped into α MASD are drastically different from those for the more frequently occuring β MASD. The linewidths of Cr3+ in α and β MASD show anomalous angular dependence. The inhomogeneous line broadening observed for β MASD could be explained by a random distribution in the orientation of the symmetry axis of the trigonal [Cr(H2O)6]3+ complex. The linewidth anomaly shows a more complicated angular dependence for α MASD; it could be that not only the orientation of the symmetry axis but also the magnitude of the axial crystal field of [Cr(H2O)6]3+ suffer random distributions.",
author = "Lou, {Ssu Hao} and Jiang-Tsu Yu",
year = "1992",
month = "1",
day = "1",
doi = "10.1016/0038-1098(92)90478-R",
language = "English",
volume = "84",
pages = "775--779",
journal = "Solid State Communications",
issn = "0038-1098",
publisher = "Elsevier Limited",
number = "7",

}

TY - JOUR

T1 - Dimorphism in methylammonium aluminum alum studied by X-ray diffraction and electron paramagnetic resonance

AU - Lou, Ssu Hao

AU - Yu, Jiang-Tsu

PY - 1992/1/1

Y1 - 1992/1/1

N2 - We have found a reliable method of growing single-phase methyl-ammonium alum (MASD) crystallising in the infrequently-occurring α alum structure; the presence of the perchlorate ion, ClO4 -, in growth solutions induces the crystallisation of α MASD crystals. Seeding the growth solution with α MASD crystals also induces crystallisation of new α MASD crystals. The X-ray powder diffraction pattern and the EPR spectrum of the Cr3+ ions doped into α MASD are drastically different from those for the more frequently occuring β MASD. The linewidths of Cr3+ in α and β MASD show anomalous angular dependence. The inhomogeneous line broadening observed for β MASD could be explained by a random distribution in the orientation of the symmetry axis of the trigonal [Cr(H2O)6]3+ complex. The linewidth anomaly shows a more complicated angular dependence for α MASD; it could be that not only the orientation of the symmetry axis but also the magnitude of the axial crystal field of [Cr(H2O)6]3+ suffer random distributions.

AB - We have found a reliable method of growing single-phase methyl-ammonium alum (MASD) crystallising in the infrequently-occurring α alum structure; the presence of the perchlorate ion, ClO4 -, in growth solutions induces the crystallisation of α MASD crystals. Seeding the growth solution with α MASD crystals also induces crystallisation of new α MASD crystals. The X-ray powder diffraction pattern and the EPR spectrum of the Cr3+ ions doped into α MASD are drastically different from those for the more frequently occuring β MASD. The linewidths of Cr3+ in α and β MASD show anomalous angular dependence. The inhomogeneous line broadening observed for β MASD could be explained by a random distribution in the orientation of the symmetry axis of the trigonal [Cr(H2O)6]3+ complex. The linewidth anomaly shows a more complicated angular dependence for α MASD; it could be that not only the orientation of the symmetry axis but also the magnitude of the axial crystal field of [Cr(H2O)6]3+ suffer random distributions.

UR - http://www.scopus.com/inward/record.url?scp=0026943948&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026943948&partnerID=8YFLogxK

U2 - 10.1016/0038-1098(92)90478-R

DO - 10.1016/0038-1098(92)90478-R

M3 - Article

AN - SCOPUS:0026943948

VL - 84

SP - 775

EP - 779

JO - Solid State Communications

JF - Solid State Communications

SN - 0038-1098

IS - 7

ER -