The crystal structure of Th<sub>2</sub>Co<sub>7</sub>

Buschow, K.H.J.

doi:10.1107/s056774087000420x

Cited by 32 publications

(5 citation statements)

References 2 publications

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“…The R2Co7 compound was found to crystallize in two polymorphic forms: a high-temperature phase modification of the hexagonal Ce2Ni7-type structure and a low-temperature phase modification of the rhombohedral Gd2Co7-type structure. These results are in agreement with those reported by Bertaut, Lemaire & Schweizer (1965) and Buschow (1970), except that whereas Buschow (1970) reported the high-and low-temperature phase modifications of this compound to be isostructural with the rhombohedral Gd2CoT-type and hexagonal Ce2Ni7-type respectively, we have observed just the opposite.…”

Section: Resultssupporting

confidence: 93%

The crystal structure of R5Co19

Khan¹

1974

Acta Crystallogr B Struct Crystallogr Cryst Chem

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Formation of the intermetallic compounds in the composition range 66-83 at. % Co of the R-Co intermetallic systems (R = rare earths) is described by the general formula RTx where x= (5n+4)/(n+ 2), n=0,1,2,3,4 ..... T= transition metals Fe, Co and Ni. Using the structural data of the already known RTx compounds for n = 0, 1 and 2, simple mathematical relations are developed, with the help of which the lattice parameters and the atomic positions for any RTx compound can be computed easily. Structural data for RsCo19 are presented. It is shown that the structures of the RTx compounds are the onedimensional long-period superstructures of the CaCus-type structure.

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Section: Resultssupporting

confidence: 93%

The crystal structure of R5Co19

Khan¹

1974

Acta Crystallogr B Struct Crystallogr Cryst Chem

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“…The transformation of SmzCov(L) into Sm2COT(h) takes place at 1080+20°C. Our results on Sm2Co7 contradict, therefore, those of Buschow (1970). Fig.…”

Section: Resultscontrasting

confidence: 87%

“…l(a) shows the Guinier X-ray pattern of Sm2Cov(h). It is seen that the reflexions are quite sharp contrary to previous findings (Buschow, 1970). The structural data for this modification of Sm2Co7 are given in Table 2.…”

Section: Resultscontrasting

confidence: 64%

A contribution to the Sm–Co phase diagram

Khan¹

1974

Acta Crystallogr Sect B

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The Co-rich part of the Sm-Co system has been investigated by X-ray diffraction, metallographic and thermoanalytic methods. The existence of five closely related compounds (Sm2Co7, SmCos_x, SmCos, SmCos+x and Sm2Co~7) has been confirmed. A tentative phase diagram of the Co-rich part of the Sm-Co system is presented. The practical difficulties encountered in the construction of this phase diagram are discussed.

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“…have commented that the Ce2Ni7 structure, as well as the CeNi3 and PuNi3 structures (Cromer & Olsen, 1959), can be considered as being formed by combinations of the MgCu2-type and CaCus-type structures. Buschow (1970) has noted that the fl-Gd2COT-type structure (Bertaut, Lemaire & Schweizer, 1965) is simply a stacking variant of the Ce2Ni7 structure and, as such, may also be considered as being composed of a combination of MgCu2-type and CaCus-type structures. These structures are therefore all closely related to the Zr2Ni7 structure.…”

Section: Discussionmentioning

confidence: 99%