Nanoscale modulations in (KLa)(CaW)O 6 and (NaLa)(CaW)O 6

Mark W. Licurse; Albina Y. Borisevich; Peter K. Davies

doi:10.1016/j.jssc.2012.03.026

Nanoscale modulations in (KLa)(CaW)O ₆ and (NaLa)(CaW)O ₆

Mark W. Licurse
, Albina Y. Borisevich
, Peter K. Davies

Research output: Contribution to journal › Article › peer-review

8 Scopus citations

Abstract

Complex nanoscale modulations are identified in two new A-site ordered perovskites, (KLa)(CaW)O ₆ and (NaLa)(CaW)O ₆. In (KLa)(CaW)O ₆, selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) show an incommensurate nanocheckerboard modulation with ∼9.4×9.4a _p periodicity (a _p≈4 Å for the cubic perovskite aristotype). For (NaLa)(CaW)O ₆ a one-dimensional modulation is observed with a ∼16(1 1 0)a _p repeat; the 〈1 1 0〉 orientation of the nanostripes is different from the 〈1 0 0〉 stripes observed in other mixed A-site systems. Studies using high temperature x-ray diffraction suggest the formation of the complex modulations is associated with small deviations from the ideal 1:1:1:1 stoichiometry of the (ALa ³)(CaW)O ₆ phases. Z-contrast images acquired on an aberration-corrected microscope provide evidence for deviations from stoichiometry with a ∼1:15 periodic arrangement of La _4/3(CaW)O ₆:(NaLa)(CaW)O ₆ nano-phases.

Original language	English
Pages (from-to)	220-224
Number of pages	5
Journal	Journal of Solid State Chemistry
Volume	191
DOIs	https://doi.org/10.1016/j.jssc.2012.03.026
State	Published - Jul 2012

Funding

This work was supported by the National Science Foundation , under grant DMR0704255 , and by the MRSEC Program , under award no. DMR05-20020 . STEM studies conducted in part at the ORNL's Shared Research Equipment (SHaRE) User Facility, which is sponsored by the Office of Basic Energy Sciences, U.S. Department of Energy.

Keywords

Modulated structures
Nanocheckerboards
Nanostripes
Perovskites
Tungstates

Access to Document

10.1016/j.jssc.2012.03.026

Cite this

@article{5580e28775ca4b7f9d93b96453376d92,

title = "Nanoscale modulations in (KLa)(CaW)O 6 and (NaLa)(CaW)O 6 ",

abstract = "Complex nanoscale modulations are identified in two new A-site ordered perovskites, (KLa)(CaW)O 6 and (NaLa)(CaW)O 6. In (KLa)(CaW)O 6, selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) show an incommensurate nanocheckerboard modulation with ∼9.4×9.4a p periodicity (a p≈4 {\AA} for the cubic perovskite aristotype). For (NaLa)(CaW)O 6 a one-dimensional modulation is observed with a ∼16(1 1 0)a p repeat; the 〈1 1 0〉 orientation of the nanostripes is different from the 〈1 0 0〉 stripes observed in other mixed A-site systems. Studies using high temperature x-ray diffraction suggest the formation of the complex modulations is associated with small deviations from the ideal 1:1:1:1 stoichiometry of the (ALa 3)(CaW)O 6 phases. Z-contrast images acquired on an aberration-corrected microscope provide evidence for deviations from stoichiometry with a ∼1:15 periodic arrangement of La 4/3(CaW)O 6:(NaLa)(CaW)O 6 nano-phases.",

keywords = "Modulated structures, Nanocheckerboards, Nanostripes, Perovskites, Tungstates",

author = "Licurse, \{Mark W.\} and Borisevich, \{Albina Y.\} and Davies, \{Peter K.\}",

year = "2012",

month = jul,

doi = "10.1016/j.jssc.2012.03.026",

language = "English",

volume = "191",

pages = "220--224",

journal = "Journal of Solid State Chemistry",

issn = "0022-4596",

publisher = "Elsevier",

}

TY - JOUR

T1 - Nanoscale modulations in (KLa)(CaW)O 6 and (NaLa)(CaW)O 6

AU - Licurse, Mark W.

AU - Borisevich, Albina Y.

AU - Davies, Peter K.

PY - 2012/7

Y1 - 2012/7

N2 - Complex nanoscale modulations are identified in two new A-site ordered perovskites, (KLa)(CaW)O 6 and (NaLa)(CaW)O 6. In (KLa)(CaW)O 6, selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) show an incommensurate nanocheckerboard modulation with ∼9.4×9.4a p periodicity (a p≈4 Å for the cubic perovskite aristotype). For (NaLa)(CaW)O 6 a one-dimensional modulation is observed with a ∼16(1 1 0)a p repeat; the 〈1 1 0〉 orientation of the nanostripes is different from the 〈1 0 0〉 stripes observed in other mixed A-site systems. Studies using high temperature x-ray diffraction suggest the formation of the complex modulations is associated with small deviations from the ideal 1:1:1:1 stoichiometry of the (ALa 3)(CaW)O 6 phases. Z-contrast images acquired on an aberration-corrected microscope provide evidence for deviations from stoichiometry with a ∼1:15 periodic arrangement of La 4/3(CaW)O 6:(NaLa)(CaW)O 6 nano-phases.

AB - Complex nanoscale modulations are identified in two new A-site ordered perovskites, (KLa)(CaW)O 6 and (NaLa)(CaW)O 6. In (KLa)(CaW)O 6, selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) show an incommensurate nanocheckerboard modulation with ∼9.4×9.4a p periodicity (a p≈4 Å for the cubic perovskite aristotype). For (NaLa)(CaW)O 6 a one-dimensional modulation is observed with a ∼16(1 1 0)a p repeat; the 〈1 1 0〉 orientation of the nanostripes is different from the 〈1 0 0〉 stripes observed in other mixed A-site systems. Studies using high temperature x-ray diffraction suggest the formation of the complex modulations is associated with small deviations from the ideal 1:1:1:1 stoichiometry of the (ALa 3)(CaW)O 6 phases. Z-contrast images acquired on an aberration-corrected microscope provide evidence for deviations from stoichiometry with a ∼1:15 periodic arrangement of La 4/3(CaW)O 6:(NaLa)(CaW)O 6 nano-phases.

KW - Modulated structures

KW - Nanocheckerboards

KW - Nanostripes

KW - Perovskites

KW - Tungstates

UR - https://www.scopus.com/pages/publications/84862200567

U2 - 10.1016/j.jssc.2012.03.026

DO - 10.1016/j.jssc.2012.03.026

M3 - Article

AN - SCOPUS:84862200567

SN - 0022-4596

VL - 191

SP - 220

EP - 224

JO - Journal of Solid State Chemistry

JF - Journal of Solid State Chemistry

ER -