Structure and Optical Properties of the Arsenide Oxides REZnAsO (RE = Y, La–Nd, Sm, Gd–Er)

Abstract

The equiatomic rare earth metal zinc arsenide oxides REZnAsO (RE ϭ Y, LaϪNd, Sm, GdϪEr) were synthesized in well crystallized form from the elements, arsenic, and ZnO in NaCl/ KCl fluxes in sealed silica ampoules. The samples were characterized by powder and single-crystal X-ray data. HoZnAsO and ErZnAsO are reported for the first time. Four structures (ZrCuSiAs type, space group P4/nmm) were refined from single-crystal X-ray diffractometer data: a ϭ 394.23(3), c ϭ 884.0(1) pm, wR2 ϭ 0.0345, 216 F 2 values for YZnAsO, a ϭ 409.56(3), c ϭ 907.0(1) pm, wR2 ϭ 0.0502, 285 F 2 values for LaZnAsO, a ϭ 397.62(4), c ϭ 889.2(2) pm, wR2 ϭ 0.0700, 216 F 2 values for GdZnAsO, and a ϭ 392.72(3), c ϭ 881.5(1) pm, wR2 ϭ 0.0580, 373 F 2 values for * Prof. Dr. R. Pöttgen

First principles study on electronic structure and optical properties of quaternary arsenide oxides YZnAsO and LaZnAsO

“…The calculated optimization lattice parameters a (nm), c (nm), V (nm 3 ) and atomic coordinates compared with available experimental data [2,5] for YZnAsO and LaZnAsO are summarized in Table 1, which show that the calculated …”

“…Calculated lattice parameters a, c, V and atomic internal coordinate z Y/La , z As compared with experimental data[5] for YZnAsO and LaZnAsO…”

“…They have similar layered structures with alternating [REO] and [ZnPn] (Pn=As, P) layers, and exhibit a wide variety of interesting electrical, optical, and magnetic properties [1−6]. YZnAsO and LaZnAsO, which are isostructural to the layered rare-earth oxypnictides REZnAsO (RE=Y, La-Nd, Sm, Gd, Er), are semiconductor compounds with band gap about 1.5− 2.3 eV in experimental investigation [2,5] or about 0.65−1.3 eV in theoretical calculation [6]. KAYANUMA et al [2] have successfully grown LaZnAsO thin films on MgO substrates.…”

“…The electrical conductivity of the undoped LaZnOAs epitaxial films is 2.0×10 −1 S/cm at room temperature, the Seebeck coefficient of the epitaxial film is positive and the optical bandgaps of LaZnOAs is estimated to be ~1.5 eV, indicating that LaZnAsO is a p-type semiconductor and may be a promising matrix for diluted magnetic semiconductors if Zn 2+ is partially replaced by a divalent transition metal, for example Mn 2+ . LINCKE et al [5] have synthesized well crystallized form REZnAsO (RE=Y, La) from the ingots of rare earth elements, arsenic, and ZnO in NaCl/ KCl fluxes in sealed silica ampoules. The REZnAsO structures consist of alternate stacks of (RE 3+ O 2− ) and (Zn 2+ As 3− ) layers with covalent RE-O and Zn-As intralayer and weak ionic interlayer bonding.…”

Competing magnetic phases and field-induced dynamics in DyRuAsO

“…CeNiAsO shows two magnetic ordering transitions associated with Ce moments, and is described as a dense Kondo lattice metal [23]. With a filled 3d shell, LnZnAsO compounds are semiconductors with band gaps near 2 eV, and form as transparent crystals with colors varying from yellow-orange to red [24]. Clearly this structure type provides fertile grounds for interesting physics accessible by simple chemical substitutions.…”