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Tetragonal PbFCl type

The FeOCl structure is met with in cations that prefer octahedral coordination. It can be approximated to some distortion of the PbFCl type. In the tetragonal PbFCl-type compounds, the corrugated M—O layers are replaced by planar M—F layers. The PbFCl structure is also found for oxyhalides (for example, in the LnOCl series from manthanum to erbium). [Pg.478]

Many lanthanide oxyhalides, MOCl (M=La—Ho), MoBr (M= lanthanides and Y) and MOI (M = La, Sm, Eu, Tm, Yb) crystallize in tetragonal PbFCl structure type [98, 137—141). However, the heavier lanthanide oxychlorides (Tm, Yb, Lu) do not crystallize in the PbFCl structure [137) probably because of the short chlorine-chlorine contacts. In the case of the oxybromides, this perturbing effect does not exist and tbe PbFCl structure is preserved through the lanthanide series and including YOBr [139). [Pg.106]

BkOCl (154), BkOBr (155), and BkOI (153,155) have been synthesized and found to exhibit the PbFCl-type tetragonal structure. Although presently unreported, BkOF certainly can be prepared and probably exhibits polymorphism. [Pg.53]

Fig. 17, Tetragonal symmetry projective view (above) and cut A-B (below) of a [LSli-layer formed by a sequence of [L4S] tetrahedrons (ideally PbFCl-type distorted CeSI-, FeOCl-, and NdSBr-types). (Redrawn from C. Dagron and F. Thevet, Ann. Chim. 6, 67 (1971), Fig. 6, p. 77.)... Fig. 17, Tetragonal symmetry projective view (above) and cut A-B (below) of a [LSli-layer formed by a sequence of [L4S] tetrahedrons (ideally PbFCl-type distorted CeSI-, FeOCl-, and NdSBr-types). (Redrawn from C. Dagron and F. Thevet, Ann. Chim. 6, 67 (1971), Fig. 6, p. 77.)...
LaMnSi is tetragonal with the PbFCl-type P4/nmm, a = 4.177, c = 7.372 (Knigenko et al., 1977 X-ray powder analysis). For sample preparation, see Y-Mn-Si. Johnson (1974/76) confirmed the structure (a = 4.185, c = 7.433) and the ferromagnetic ordering temperatureof = 305 K. Sample preparation as for YMnSi. LaMnSi can also be obtained by solid state reactions from LaSi and Mn in sealed silica tubes lined with graphite (800 °C, 3d). [Pg.125]

According to X-ray powder diffraction data by Bodak et al. (1970) YbFeSi is tetragonal with the PbFCl-type of structure [P4/nmm, a = 3.972(3), c = 6.784(5)]. For sample preparation, see CeFeSi. [Pg.242]

The hydrotellurides (RH ,)Te, from La to Pr. These phases are hydrogen deficient. They are tetragonal, probably of the PbFCl-type (Carter, 1961). [Pg.69]


See other pages where Tetragonal PbFCl type is mentioned: [Pg.468]    [Pg.287]    [Pg.495]    [Pg.468]    [Pg.287]    [Pg.495]    [Pg.71]    [Pg.106]    [Pg.419]    [Pg.55]    [Pg.589]    [Pg.9]    [Pg.148]    [Pg.160]    [Pg.190]    [Pg.76]    [Pg.142]    [Pg.208]    [Pg.290]    [Pg.314]    [Pg.483]    [Pg.382]    [Pg.382]    [Pg.588]   
See also in sourсe #XX -- [ Pg.468 ]




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