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Title: Three-layer Aurivillius phases containing magnetic transition metal cations : Bi{sub 2-x}Sr{sub 2+x}(Nb,Ta){sub 2+x}M{sub 1-x}O{sub 12}, M = Ru{sub 4+}, Ir{sub 4+}, Mn{sub 4+}, x {approx} 0.5.

Abstract

We report the synthesis of Aurivillius-type phases incorporating magnetic M{sup 4+} cations (M=Mn, Ru, Ir), based on the substitution of M{sup 4+} for Ti{sup 4+} in Bi{sub 2}Sr{sub 2}(Nb,Ta){sub 2}TiO{sub 12}. The key to incorporating these magnetic transition metal cations appears to be the partial substitution of Sr{sup 2+} for Bi{sup 3+} in the {alpha}-PbO-type layer of the Aurivillius phase, leading to a concomitant decrease in the M{sup 4+} content; i.e., the composition of the prepared compounds was Bi{sub 2-x}Sr{sub 2+x}(Nb,Ta){sub 2+x}M{sub 1-x}O{sub 12}, x {approx} 0.5. These compounds only exist over a narrow range of x, between an apparent minimum (x {approx} 0.4) Sr{sup 2+} content in the {alpha}-PbO-type [Bi{sub 2}O{sub 2}] layer required for Aurivillius phases to form with magnetic M{sup 4+} cations, and an apparent maximum (x {approx} 0.6) Sr{sup 2+} substitution in this [Bi{sub 2}O{sub 2}] layer. Rietveld-refinement of synchrotron X-ray powder diffraction data making use of anomalous dispersion at the Nb and Ru K edges show that the overwhelming majority of the incorporated M cations occupy the central of the three MO{sub 6} octahedral layers in the perovskite-type block. Magnetic susceptibility measurements are presented and discussed in the context of the potential for multiferroic (magnetoelectric)more » properties in these materials.« less

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); AUSTRALIAN INST. OF SCIENCE AND ENGINEERING
OSTI Identifier:
940687
Report Number(s):
ANL/XSD/JA-57593
Journal ID: ISSN 0022-4596; JSSCBI; TRN: US0807182
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Solid State Chem.; Journal Volume: 180; Journal Issue: 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
43 PARTICLE ACCELERATORS; CATIONS; DIFFRACTION; MAGNETIC SUSCEPTIBILITY; SYNCHROTRONS; SYNTHESIS; TRANSITION ELEMENTS

Citation Formats

Sharma, N., Wrighter, G. E., Chen, P. Y., Kennedy, B. J., Lee, P.L., Ling, C. D., X-Ray Science Division, Univ. of Sydney, and Bragg Inst. Three-layer Aurivillius phases containing magnetic transition metal cations : Bi{sub 2-x}Sr{sub 2+x}(Nb,Ta){sub 2+x}M{sub 1-x}O{sub 12}, M = Ru{sub 4+}, Ir{sub 4+}, Mn{sub 4+}, x {approx} 0.5.. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2006.10.031.
Sharma, N., Wrighter, G. E., Chen, P. Y., Kennedy, B. J., Lee, P.L., Ling, C. D., X-Ray Science Division, Univ. of Sydney, & Bragg Inst. Three-layer Aurivillius phases containing magnetic transition metal cations : Bi{sub 2-x}Sr{sub 2+x}(Nb,Ta){sub 2+x}M{sub 1-x}O{sub 12}, M = Ru{sub 4+}, Ir{sub 4+}, Mn{sub 4+}, x {approx} 0.5.. United States. doi:10.1016/j.jssc.2006.10.031.
Sharma, N., Wrighter, G. E., Chen, P. Y., Kennedy, B. J., Lee, P.L., Ling, C. D., X-Ray Science Division, Univ. of Sydney, and Bragg Inst. Mon . "Three-layer Aurivillius phases containing magnetic transition metal cations : Bi{sub 2-x}Sr{sub 2+x}(Nb,Ta){sub 2+x}M{sub 1-x}O{sub 12}, M = Ru{sub 4+}, Ir{sub 4+}, Mn{sub 4+}, x {approx} 0.5.". United States. doi:10.1016/j.jssc.2006.10.031.
@article{osti_940687,
title = {Three-layer Aurivillius phases containing magnetic transition metal cations : Bi{sub 2-x}Sr{sub 2+x}(Nb,Ta){sub 2+x}M{sub 1-x}O{sub 12}, M = Ru{sub 4+}, Ir{sub 4+}, Mn{sub 4+}, x {approx} 0.5.},
author = {Sharma, N. and Wrighter, G. E. and Chen, P. Y. and Kennedy, B. J. and Lee, P.L. and Ling, C. D. and X-Ray Science Division and Univ. of Sydney and Bragg Inst.},
abstractNote = {We report the synthesis of Aurivillius-type phases incorporating magnetic M{sup 4+} cations (M=Mn, Ru, Ir), based on the substitution of M{sup 4+} for Ti{sup 4+} in Bi{sub 2}Sr{sub 2}(Nb,Ta){sub 2}TiO{sub 12}. The key to incorporating these magnetic transition metal cations appears to be the partial substitution of Sr{sup 2+} for Bi{sup 3+} in the {alpha}-PbO-type layer of the Aurivillius phase, leading to a concomitant decrease in the M{sup 4+} content; i.e., the composition of the prepared compounds was Bi{sub 2-x}Sr{sub 2+x}(Nb,Ta){sub 2+x}M{sub 1-x}O{sub 12}, x {approx} 0.5. These compounds only exist over a narrow range of x, between an apparent minimum (x {approx} 0.4) Sr{sup 2+} content in the {alpha}-PbO-type [Bi{sub 2}O{sub 2}] layer required for Aurivillius phases to form with magnetic M{sup 4+} cations, and an apparent maximum (x {approx} 0.6) Sr{sup 2+} substitution in this [Bi{sub 2}O{sub 2}] layer. Rietveld-refinement of synchrotron X-ray powder diffraction data making use of anomalous dispersion at the Nb and Ru K edges show that the overwhelming majority of the incorporated M cations occupy the central of the three MO{sub 6} octahedral layers in the perovskite-type block. Magnetic susceptibility measurements are presented and discussed in the context of the potential for multiferroic (magnetoelectric) properties in these materials.},
doi = {10.1016/j.jssc.2006.10.031},
journal = {J. Solid State Chem.},
number = 2007,
volume = 180,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • We report the synthesis of Aurivillius-type phases incorporating magnetic M {sup 4+} cations (M=Mn, Ru, Ir), based on the substitution of M {sup 4+} for Ti{sup 4+} in Bi{sub 2}Sr{sub 2}(Nb,Ta){sub 2}TiO{sub 12}. Key to incorporating these magnetic transition metal cations appears to be the partial substitution of Sr{sup 2+} for Bi{sup 3+} in the {alpha}-PbO-type layer of the Aurivillius phase, leading to a concomitant decrease in the M {sup 4+} content; i.e., the composition of the prepared compounds was Bi{sub 2-} {sub x} Sr{sub 2+} {sub x} (Nb,Ta){sub 2+} {sub x}M {sub 1-} {sub x} O{sub 12}, x{approx}0.5. Thesemore » compounds only exist over a narrow range of x, between an apparent minimum (x{approx}0.4) Sr{sup 2+} content in the {alpha}-PbO-type [Bi{sub 2}O{sub 2}] layer required for Aurivillius phases to form with magnetic M {sup 4+} cations, and an apparent maximum (x{approx}0.6) Sr{sup 2+} substitution in this [Bi{sub 2}O{sub 2}] layer. Rietveld-refinement of synchrotron X-ray powder diffraction data making use of anomalous dispersion at the Nb and Ru K edges show that the overwhelming majority of the incorporated M cations occupy the central of the three MO{sub 6} octahedral layers in the perovskite-type block. Magnetic susceptibility measurements are presented and discussed in the context of the potential for multiferroic (magnetoelectric) properties in these materials. - Graphical abstract: Structure of Bi{sub 1.5}Sr{sub 2.5}Nb{sub 2.5}Ru{sub 0.5}O{sub 12}.« less
  • Ferroelectric Sr{sub 1-x}Ba{sub x}Bi{sub 2}(Nb{sub 0.5}Ta{sub 0.5}){sub 2}O{sub 9} and Sr{sub 0.5}Ba{sub 0.5}Bi{sub 2}(Nb{sub 1-y}Ta{sub y}){sub 2}O{sub 9} were synthesized by solid state reaction route. X-ray diffraction studies confirm the formation of single phase layered perovskite solid solutions over a wide range of compositions (x=y=0.0, 0.25, 0.50, 0.75 and 1). The lattice parameters and the Curie temperature (T{sub c}) have been found to have linear dependence on x and y. Transmission electron microscopy (TEM) suggest the lowering of orthorhombic distortion with increasing Ba{sup 2+} substitution. Variations in microstructural features as a function of x and y were monitored by scanningmore » electron microscopy (SEM). The dielectric constant at room temperature increases with increase in both x and y. Interestingly Ba{sup 2+} substitution on Sr{sup 2+} site induces diffused phase transition and diffuseness increases with increasing Ba{sup 2+} concentration.« less
  • The n=3 Aurivillius material Bi{sub 2}Sr{sub 2}Nb{sub 2.5}Fe{sub 0.5}O{sub 12} is investigated and combined structural refinements using neutron powder diffraction (NPD) and X-ray powder diffraction data (XRPD) data reveal that the material adopts a disordered, tetragonal (I4/mmm) structure at temperatures down to 2 K. Significant ordering of Fe{sup 3+} and Nb{sup 5+} over the two B sites is observed and possible driving forces for this ordering are discussed. Some disorder of Sr{sup 2+} and Bi{sup 3+} over the M and A sites is found and is consistent with relieving strain due to size mismatch. Highly anisotropic thermal parameters for somemore » oxygen sites suggest that the local structure may be slightly distorted with some rotation of the octahedra. Magnetic measurements show that the material behaves as a Curie-Weiss paramagnet in the temperature range studied with no evidence of any long-range magnetic interactions. Solid solutions including Bi{sub 3-x}Sr{sub x}Nb{sub 2}FeO{sub 12}, Bi{sub 2}Sr{sub 2-x}La{sub x}Nb{sub 2}FeO{sub 12} and Bi{sub 2}Sr{sub 2}Nb{sub 3-x}Fe{sub x}O{sub 12} were investigated but single-phase materials were only successfully synthesised for a narrow composition range in the Bi{sub 2}Sr{sub 2}Nb{sub 3-x}Fe{sub x}O{sub 12} system. - Graphical abstract: We report here the synthesis and characterisation of the Aurivillius material Bi{sub 2}Sr{sub 2}Nb{sub 2.5}Fe{sub 0.5}O{sub 12}. Combined Rietveld refinements using NPD and XRPD data have been used to investigate the structure and suggest that the material shows significant cation ordering as well as some local structural distortions. Bi{sub 2}Sr{sub 2}Nb{sub 2.5}Fe{sub 0.5}O{sub 12} is paramagnetic in the temperature range studied.« less
  • This work is dedicated to investigation of new disordered bismuth-containing oxy-phosphates compounds with an original structure type. As previously observed in this series, they are formed of [M{sub 4}Bi{sub 2n-2}O{sub 2n}]{sup x+} polycationic ribbons of width n O(Bi,M){sub 4} tetrahedra, surrounded by PO{sub 4} groups. In the new crystal structure type, double (=D), triple (=T) and tunnels (=t) alternate along a common axis obeying the TtDtTtDt/TTtTTt sequence in respect to a nomenclature previously described and recalled in this work. The existence this new polymorph has first been detected by electron diffraction in a multi-phased sample. Then, the crystal structure type,more » i.e., the TtDtTtDt/TTtTTt sequence, has been deduced from HREM images help to a contrast-interpreting code available for these series of polycations-formed compounds. The subsequent compounds formulation leads to a number of new materials that verify the general formula: [Bi{sub 2}(Bi,M){sub 4}O{sub 4}]{sub 2} [Bi{sub 4}(Bi,M){sub 4}O{sub 6}]{sub 6} (PO{sub 4}){sub 28} M{sub x}, with x=<12 and M=Cu{sup 2+}, Cd{sup 2+} cations. Single crystals of the nominal [O6Bi{sub 4.57}Cd{sub 3.43}]{sub 4}{sup +8.57} [O{sub 6}Bi{sub 4}Cd{sub 4}]{sub 2}{sup +8} [O{sub 4}Bi{sub 2}Cd{sub 3.56}Cu{sub 0.44}]{sub 2}{sup +6} (PO{sub 4}){sub 28} Cu{sub 10.86} have been prepared in a further stage and confirms the predicted crystal structure, Bi{sub {approx}}{sub 3.785}Cd{sub {approx}}{sub 3.575}Cu{sub {approx}}{sub 1.5}(PO{sub 4}){sub 3.5}O{sub 5.5}= , a=11.506(8)A, b=5.416(4)A, c=53.94 (4)A, {beta}=90.10(1){sup o}, RF=0.0835, RwF=0.0993, SG=A2/m, Z=8. As already observed for other elements of this family such as Bi{sub {approx}}{sub 1.2}M{sub {approx}}{sub 1.2}O{sub 1.5}(PO{sub 4}), Bi{sub {approx}}{sub 6.2}Cu{sub {approx}}{sub 6.2}O{sub 8}(PO{sub 4}){sub 5} or Bi{sub {approx}}{sub 3}Cd{sub {approx}}{sub 3.72}M{sub {approx}}{sub 1.28}O{sub 5}(PO{sub 4}){sub 3} (M=Cu, Co, Zn), this compound shows an additional example of PO{sub 4} disorder due to the presence of mixed Bi{sup 3+}/M{sup 2+} sites at the edges of ribbons. The origin and consequence of this so-called disorder mostly occurring on PO{sub 4} configurations is intensively discussed and has been characterized by infrared spectroscopy and by neutron diffraction on similar compounds. It is noticeable that the great number of antagonist PO{sub 4} configurations may order along the b-axis within a large periodicity which involves incommensurate lattice.« less
  • We have investigated Pr{sub 1.5}Ce{sub 0.5}{ital M}Sr{sub 2}Cu{sub 2}O{sub {ital z}} ({ital z}=9 or 10) materials ({ital M}=Ta, In, and Nb+Ga) by complementary experimental techniques. All materials studied are not superconducting. Magnetic susceptibility studies for {ital M}=Ta reveal one magnetic anomaly at 23 K and irreversibility phenomena at higher temperatures. The presence of 0.5{percent} {sup 57}Fe dramatically affects the positions of the anomalies, and M{umlt o}ssbauer spectroscopy studies (MS) reveal that the Cu(2) sites are magnetically ordered below {ital T}{sub {ital N}}(Cu)=130 K. This low {ital T}{sub {ital N}}(Cu) obtained is discussed. No specific heat anomaly was observed at 23more » K, suggesting that the Pr sublattice does not order magnetically, and the anomalies in the susceptibility originate from the Cu moments. No anomalies in the susceptibility curves are found for {ital M}=In and Nb+Ga compounds. However, MS indicate that for the mixed compound, the Cu sites are magnetically ordered at low temperatures. The magnetic behavior of {ital M}=Ta is compared to similar systems with two anomalies for {ital M}=Nb at 11 and 52 K, and three anomalies for {ital M}=Ga at 12, 52, and 94 K. X-ray absorption spectroscopy (XAS) indicates that in all materials studied, the Pr has a mixed valence close to 3. The Pr valence does not change with temperature. {copyright} {ital 1996 The American Physical Society.}« less