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Title: Structure, thermodynamic, and magnetic properties of Ln[sub 4]PdO[sub 7] with Ln = La, Nd, Sm, Eu, and Gd

Abstract

The structure of Nd[sub 4]PdO[sub 7] has been determined and refined using the Rietveld method and combined CuK[alpha][sub 1] X-ray and neutron powder data in space group P[bar 1] with unit cell a = 15.972(2), b = 7.1927(7), c = 6.9160(6) [angstrom], [alpha] = 96.299(4), [beta] = 131.643(3), [gamma] = 121.438(3)[degree], V = 353.83(6) [angstrom][sup 3] and Z = 2, to R[sub F] = 2.0% (neutron data) and R[sub F] = 6.2% (X-ray data). The structure is closely related to the monoclinic La[sub 4]PdO[sub 7] structure and exhibits Nd atoms coordinated by seven O atoms and Pd atoms coordinated by a square of O atoms. Isolated chains of trans-corner-sharing PdO[sub 4] squares are straight in the La[sub 4]PdO[sub 7] structure and staggered in the Nd[sub 4]PdO[sub 7] structure. Electron and X-ray powder diffraction data show that Ln[sub 4]PdO[sub 7] with Ln = Sm, Eu, and Gd is isostructural with Nd[sub 4]PdO[sub 7]. The enthalpies of dissolution of Ln[sub 4]PdO[sub 7] (Ln = La, Nd) in 1.000 M HCl have been measured with an in-house built calorimeter, and from these values the enthalpies of formation for the compounds have been calculated. The decomposition temperatures of Ln[sub 4]PdO[sub 7] with Ln =more » La and Nd in oxygen have been determined by thermogravimetric measurements and found to decrease from 1645 [+-] 10 K for La[sub 4]PdO[sub 7] to 1540 [+-] 10 K for Nd[sub 4]PdO[sub 7]. Using these data, an Ellingham diagram has been constructed assuming temperature-independent [Delta]H[sub f][degree] and [Delta]S[sub f][degree]. The magnetic susceptibilities of Ln[sub 4]PdO[sub 7] with Ln = La, Nd, Sm, Eu, Gd, recorded in the temperature range 10--320 K, were found to be in agreement with the expected ones for noninteracting Ln[sup 3+] ions.« less

Authors:
; ;  [1]
  1. (Stockholm Univ. (Sweden))
Publication Date:
OSTI Identifier:
6068160
Resource Type:
Journal Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 146:2; Journal ID: ISSN 0022-4596
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CALORIMETRY; CRYSTAL STRUCTURE; EXPERIMENTAL DATA; LATTICE PARAMETERS; MAGNETIC PROPERTIES; NEUTRON DIFFRACTION; OXIDES; PALLADIUM OXIDES; RARE EARTH COMPOUNDS; THERMODYNAMIC PROPERTIES; X-RAY DIFFRACTION; CHALCOGENIDES; COHERENT SCATTERING; DATA; DIFFRACTION; INFORMATION; NUMERICAL DATA; OXYGEN COMPOUNDS; PALLADIUM COMPOUNDS; PHYSICAL PROPERTIES; SCATTERING; TRANSITION ELEMENT COMPOUNDS; 360202* - Ceramics, Cermets, & Refractories- Structure & Phase Studies; 360204 - Ceramics, Cermets, & Refractories- Physical Properties

Citation Formats

Andersson, M., Grins, J., and Nygren, M. Structure, thermodynamic, and magnetic properties of Ln[sub 4]PdO[sub 7] with Ln = La, Nd, Sm, Eu, and Gd. United States: N. p., 1999. Web. doi:10.1006/jssc.1999.8387.
Andersson, M., Grins, J., & Nygren, M. Structure, thermodynamic, and magnetic properties of Ln[sub 4]PdO[sub 7] with Ln = La, Nd, Sm, Eu, and Gd. United States. doi:10.1006/jssc.1999.8387.
Andersson, M., Grins, J., and Nygren, M. Wed . "Structure, thermodynamic, and magnetic properties of Ln[sub 4]PdO[sub 7] with Ln = La, Nd, Sm, Eu, and Gd". United States. doi:10.1006/jssc.1999.8387.
@article{osti_6068160,
title = {Structure, thermodynamic, and magnetic properties of Ln[sub 4]PdO[sub 7] with Ln = La, Nd, Sm, Eu, and Gd},
author = {Andersson, M. and Grins, J. and Nygren, M.},
abstractNote = {The structure of Nd[sub 4]PdO[sub 7] has been determined and refined using the Rietveld method and combined CuK[alpha][sub 1] X-ray and neutron powder data in space group P[bar 1] with unit cell a = 15.972(2), b = 7.1927(7), c = 6.9160(6) [angstrom], [alpha] = 96.299(4), [beta] = 131.643(3), [gamma] = 121.438(3)[degree], V = 353.83(6) [angstrom][sup 3] and Z = 2, to R[sub F] = 2.0% (neutron data) and R[sub F] = 6.2% (X-ray data). The structure is closely related to the monoclinic La[sub 4]PdO[sub 7] structure and exhibits Nd atoms coordinated by seven O atoms and Pd atoms coordinated by a square of O atoms. Isolated chains of trans-corner-sharing PdO[sub 4] squares are straight in the La[sub 4]PdO[sub 7] structure and staggered in the Nd[sub 4]PdO[sub 7] structure. Electron and X-ray powder diffraction data show that Ln[sub 4]PdO[sub 7] with Ln = Sm, Eu, and Gd is isostructural with Nd[sub 4]PdO[sub 7]. The enthalpies of dissolution of Ln[sub 4]PdO[sub 7] (Ln = La, Nd) in 1.000 M HCl have been measured with an in-house built calorimeter, and from these values the enthalpies of formation for the compounds have been calculated. The decomposition temperatures of Ln[sub 4]PdO[sub 7] with Ln = La and Nd in oxygen have been determined by thermogravimetric measurements and found to decrease from 1645 [+-] 10 K for La[sub 4]PdO[sub 7] to 1540 [+-] 10 K for Nd[sub 4]PdO[sub 7]. Using these data, an Ellingham diagram has been constructed assuming temperature-independent [Delta]H[sub f][degree] and [Delta]S[sub f][degree]. The magnetic susceptibilities of Ln[sub 4]PdO[sub 7] with Ln = La, Nd, Sm, Eu, Gd, recorded in the temperature range 10--320 K, were found to be in agreement with the expected ones for noninteracting Ln[sup 3+] ions.},
doi = {10.1006/jssc.1999.8387},
journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = ,
volume = 146:2,
place = {United States},
year = {1999},
month = {9}
}