Structure and thermal expansion properties of solid solution Nd2−xErxW3O12 ( and )

The crystal structure and thermal expansion properties of solid solutions Ln2−xDyxW3O12 (Ln=Er and Y)

“…Thus, it is not surprise that Er 1.6 Dy 0.4 W 3 O 12 exhibits stronger negative thermal expansion than Er 2 W 3 O 12. This phenomenon is in good agreement with our previous works [13][14][15] where Table 3 Lattice parameter changing with temperature…”

“…structure and thermal expansion properties of solid solutions forming from mixing the orthorhombic compound and monoclinic compound [12]. For example, we have previously reported our work on solid solutions of Er 2−x B x W 3 O 12 (B = Sm, Nd and Ce) [13][14][15]. Here, we report our work on the structures, thermal expansion properties and phase transition of Ln 2−x Dy x W 3 O 12 (Ln = Er and Y) by using RT and high temperature X-ray diffraction, thermogravimetric (TG) and differential thermal analysis (DTA).…”

Two Decades of Negative Thermal Expansion Research: Where Do We Stand?

“…Ln 2 M 3 O 12 compositions with larger lanthanides crystallize in structures that adopt higher coordination numbers (7 or 8) for the A-site. However, for solid solutions of two trivalent cations, significant amounts of larger Ln 3+ can be incorporated into the scandium tungstate structure, as evidenced by reports of Er 2−x Ce x W 3 O 12 (x ≤ 0.4) [118], Er 2−x Sm x W 3 O 12 (x ≤ 0.5) [119], Er 2−x Nd x W 3 O 12 (x ≤ 0.5) [120], Er 2−x Dy x W 3 O 12 (x ≤ 0.7) [121], Y 2−x Dy x W 3 O 12 (x ≤ 1.0) [121], and Y 2−x Nd x W 3 O 12 (x ≤ 0.4) [122]. In addition, substitution with aliovalent cations has been achieved in AP 2 MO 12 [123,124] and MgAM 3 O 12 (A = Zr, Hf; M = Mo, W) [125,126,127].…”

“…As a result, expansion tends to become more negative with increasing size of A 3+ , reaching values of −7.0 × 10 −6 K −1 in Y 2 W 3 O 12 [129] and −9.3 × 10 −6 K −1 in Y 2 Mo 3 O 12 . Additional slight decreases have been achieved in solid solutions of these compounds with larger lanthanides [118,119,120,121,122]. In contrast, Al 2 W 3 O 12 has been reported to show low positive expansion with an α l value of +2.2 × 10 −6 K −1 [5].…”

Preparation, Characterization and Photocatalytic Studies of Cr2(MoO4)3 and Nitrogen-Doped Cr2(MoO4)3

“…The structure of these materials consists of corner-sharing AO 6 octahedra and MO 4 tetrahedra. Several studies on the thermal expansion properties of tungstates and molybdates of A 2 M 3 O 12 family and their solid solutions have been reported [8][9][10][11][12][13]. The A 3+ cation in A 2 M 3 O 12 can be occupied by a transition or rare earth cation indicating its compositional flexibility.…”