Cation disorder in Ga1212

Kevin B. Greenwood, Donggeun Ko, Douglas A. Vander Griend, Gregory M. Sarjeant, John W. Milgram, Elizabeth S. Garrity, Deborah I. DeLoach, Kenneth R Poeppelmeier, Paul A. Salvador, Thomas O Mason

Research output: Contribution to journalArticle

Abstract

Substitution of calcium for strontium in Lnsr(2-x)Ca(x)Cu2GaO7 (Ln = La, Pr, Nd, Gd, Ho, Er, Tm, and Yb) materials at ambient pressure and 975 °C results in complete substitution of calcium for strontium in the lanthanum and praseodymium systems and partial substitution in the other lanthanide systems. The calcium saturation level depends on the size of the Ln cation, and in all cases, a decrease in the lattice parameters with calcium concentration was, observed until a common, lower bound, average A-cation size is reached. Site occupancies from X-ray and neutron diffraction experiments for LnSr(2-x)Ca(x)Cu2GaO7 (x = 0 and x = 2) confirm that the A-cations distribute between the two blocking-layer sites and the active-layer site based on size. A quantitative link between cation distribution and relative site-specific cation enthalpy for calcium, strontium, and lanthanum within the gallate structure is derived. The cation distribution in other similar materials can potentially be modeled.

Original languageEnglish
Pages (from-to)3386-3391
Number of pages6
JournalInorganic Chemistry
Volume39
Issue number15
DOIs
Publication statusPublished - Jul 24 2000

ASJC Scopus subject areas

  • Inorganic Chemistry

Fingerprint Dive into the research topics of 'Cation disorder in Ga1212'. Together they form a unique fingerprint.

  • Cite this

    Greenwood, K. B., Ko, D., Vander Griend, D. A., Sarjeant, G. M., Milgram, J. W., Garrity, E. S., DeLoach, D. I., Poeppelmeier, K. R., Salvador, P. A., & Mason, T. O. (2000). Cation disorder in Ga1212. Inorganic Chemistry, 39(15), 3386-3391. https://doi.org/10.1021/ic0002667