Lattice parameters and cell volume

Figure 1. Variation of the lattice parameters and cell volume (inset figure) with (rA) of Lno.TBaojMnOj with Ln = La, Nd and Gd.

Figure 6. Lattice parameters and cell volume versus temperature in air for Ba2YCu307.

Figure 1. Concentration dependencies of the lattice parameters in the CaTi03-La2/iTi03 system. Lattice parameters and cell volumes are reduced to perovskite-like cell.

Figure 5. Perovskite lattice parameters and cell volumes of (l-x)(La2/3Ti03)-x(CaTi03) and (l-x)(La2/3Ti03)-x (LaCr03) solid solutions.

FIGURE 3 Temperature dependencies of the normalized lattice parameters and cell volumes of the rhombohedral phase of PrAl03. Solid symbols indicate the HT data of Howard et al. (2000), open symbols indicate the LT data reported by Vasylechko (unpublished data). 

Another t)rpe of phase transition in NdAlOa, namely the LT transformation from the rhombohedral to orthorhombic structure, has been predicted at 16 K from the extrapolation of transition temperatures in the Ndi, Smj A103 solid solution (Yoshikawa et al., 1998). This transition, however, was not confirmed using s)mchrotron powder diffraction data collected in situ at temperatures down to 12 K (Vasylechko et al., 2007b) and neutron diffraction measurements at 0.5 and 1 K (Palacios et al., 2003). Figure 5 displays the temperature evolution of the lattice parameters and cell volume of NdA103. Structural parameters of the rhombohedral phase of NdAlOs over a broad temperature range are given in Table 8. 

In the LaAlQ3—NdA103 pseudo-binary system, a continuous solid solution with rhombohedral structure exists at RT. Lattice parameters and cell volume of the... 

FIGURE 20 Temperature dependencies of normalized lattice parameters and cell volume of YAIO3 according to Vasylechko et al. (2003a) (solid symbols) and Chaix-Pluchery et al. (2005) (open symbols). For comparison, the data for YAlo.sjMgo.osOj-x (Ranlov and Nielsen, 1995), crossed symbols are also shown. The dashed lines are polynomial fits Op(7) = 3.6608(8) [1 + 8.3(6) x... 

PrAlOa forms continuous solid solutions with the isostructural lanthanum and neodymium aluminates in the whole range of concentrations. Rhombohedral lattice parameters and cell volumes of Pr1 j.Laj.AlO3 and Pri j Ndj A103 samples... 

FIGURE 26 Concentration dependencies of the normalized lattice parameters and cell volumes of rhombohedral (Rh) and orthorhombic (O) solid solutions La,, RjtAl03 (R = Sm, Eu, Gd, Tb, Er, Y) at RT according to Basyuk et al. (2007a). The shaded areas correspond to two-phase regions. 

FIGURE 64 Thermal behaviour of lattice parameters and cell volumes for selected La, R tGaOj solid solutions. Solid points are from neutron powder diffraction (Aleksiyko et al., 2001), open points are from HRPD and SR. The letters O and Rh designate orthorhombic and rhombohedral phases, respectively. The shaded areas correspond to two-phase regions. The vertical dotted lines separate the regions with different ratios of the lattice parameters. 

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