Intermediate-valent CeCoAl - a commensurate modulated structure with short Ce-Co distances
| hal.structure.identifier | Institut für Anorganische und Analytische Chemie | |
| dc.contributor.author | NIEHAUS, Oliver | |
| hal.structure.identifier | Institut für Anorganische und Analytische Chemie | |
| dc.contributor.author | HOFFMANN, Rolf-Dieter | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | TENCÉ, Sophie | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | CHEVALIER, Bernard | |
| hal.structure.identifier | Institut für Anorganische und Analytische Chemie | |
| dc.contributor.author | PÖTTGEN, Rainer | |
| dc.date.issued | 2015 | |
| dc.identifier.issn | 0044-2968 | |
| dc.description.abstractEn | CeCoAl was synthesized by melting of theelementsin a sealed niobium tube in an inductionfurnace.Annealing of the sample gave access to a singlephase sample. Its structure was refined on the basis of single-crystal X-ray diffractometer data at different temperatures.Above 271 K CeCoAl crystallizes in its own structuretype in the space group C2/m [a = 1107.4(2), b = 440.6(1)and c = 479.6(1) pm, β = 104.6(1)°]. Data obtained at 300 Klead to 511 F 2 values with 20 variables and a residual of[I ≥ 3σ(I)] wR = 0.0539. Below 271 K satellites give rise tothe superspace group C2/m(α0γ)00; α = 2/3, γ = 2/5 with atemperature independent q-vector. For the 90 K data (alsofor 180 and 220 K) the commensurate modulated structurecould be refined with 4817 F 2 values, 129 variables andresiduals of wR = 0.0347 (main), wR = 0.1927 (satellites 1storder), wR = 0.1541 (satellites 2nd order) and wR = 0.1768(satellites 3rd order) [a = 1107.5(1), b = 440.3(1) andc = 479.0(1) pm, β = 104.7(1)°]. For the three temperaturesonly minor variations of the modulation amplitudes areobserved. The relation of the low temperature (3+1)D 3a ×5c approximant and the room temperature 3D structureis discussed on the basis of a group–subgroup relation.By investigation of the heat capacity, the phase transitioncould be identified as a second order one with a transitiontemperature of 271 K. Magnetic measurements clearlyprove the intermediate cerium valence which is in linewith the short Ce–Co distances. | |
| dc.language.iso | en | |
| dc.publisher | De Gruyter | |
| dc.subject.en | cerium | |
| dc.subject.en | group-subgroup scheme | |
| dc.subject.en | intermediate valence compound | |
| dc.subject.en | modulated structure | |
| dc.title.en | Intermediate-valent CeCoAl - a commensurate modulated structure with short Ce-Co distances | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1515/zkri-2015-1856 | |
| dc.subject.hal | Chimie/Matériaux | |
| bordeaux.journal | Zeitschrift für Kristallographie | |
| bordeaux.page | 579-591 | |
| bordeaux.volume | 230 | |
| bordeaux.issue | 9-10 | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-01193301 | |
| hal.version | 1 | |
| hal.popular | non | |
| hal.audience | Internationale | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-01193301v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Zeitschrift%20f%C3%BCr%20Kristallographie&rft.date=2015&rft.volume=230&rft.issue=9-10&rft.spage=579-591&rft.epage=579-591&rft.eissn=0044-2968&rft.issn=0044-2968&rft.au=NIEHAUS,%20Oliver&HOFFMANN,%20Rolf-Dieter&TENC%C3%89,%20Sophie&CHEVALIER,%20Bernard&P%C3%96TTGEN,%20Rainer&rft.genre=article |
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