Orientation control of KNbO3 film grown on glass substrates by Ca2Nb3O10− nanosheets seed layer

Abstract

KNbO 3 films grown on two-dimensional Ca 2 Nb 3 O 10 nanosheets covering glass substrate.  (001) preferential orientation induced by subjacent nanosheets layer.  Similar microstructure as epitaxial film grown on (100)SrTiO 3 .

Highly Transparent and Conductive Indium‐Free Vanadates Crystallized at Reduced Temperature on Glass Using a 2D Transparent Nanosheet Seed Layer

“…NS are obtained by an exfoliation process of various layered oxides [31] and transferred by Langmuir-Blodgett (LB) method (Figure 1a,b) [32] on substrates that, when used bare, are non-adapted for complex oxide deposition, such as silicon or glass. The exceptionally rich structural diversity of NS makes them interesting growth templates for oxides [30,[33][34][35][36][37][38][39][40] or metals. [41] SVO has a cubic perovskite structure with a lattice parameter a = 0.384(1) nm [42] whereas CVO is orthorhombically (o) distorted with pseudo-cubic (pc) a pc = a o /√2 = b o /√2 = c o /2 ≈0.377(1) nm.…”

“…[41] SVO has a cubic perovskite structure with a lattice parameter a = 0.384(1) nm [42] whereas CVO is orthorhombically (o) distorted with pseudo-cubic (pc) a pc = a o /√2 = b o /√2 = c o /2 ≈0.377(1) nm. [43] An adapted NS system would therefore be Ca 2 Nb 3 O 10 − (CNO) niobate nanosheets with an in-plane square lattice and a parameter a NS = 0.3854 nm [40] (Figure 1a), leading to a misfit of −0.34% for SVO and −2.14% for CVO. Moreover, CNO NS exhibit a good thermal stability, of up to 800 °C, [31,35] suitable for the growth of epitaxial CVO and SVO films crystallizing at temperatures of ≈400 °C.…”

“…This deterioration may be explained by a structural degradation of the CNO NS with T G , [ 31 ] but also by the glass transformation above the strain point (669 °C), which cannot be completely ruled out for thin films deposited at 700 °C. In particular, at T G higher than 650 °C, we evidenced by energy dispersive X‐ray spectroscopy (EDXS) coupled to transmission electron microscopy (TEM) and depth chemical profiling by X‐ray photoelectron spectroscopy (XPS) (see Supporting Information) the cationic out‐diffusion of Si and Nb into the vanadate films, a mechanism well identified leading to the degradation of the perovskite structure and its functional properties, [ 40 ] as is also the possible oxygen loss in the crystalline structure. [ 19 ]…”

“…The preparation of the exfoliated Ca 2 Nb 3 O 10 − nanosheets starting from powder of KCa 2 Nb 3 O 10 oxide is described in detail in the references. [39,40] The obtained nanosheets in colloidal solution were deposited on two side polished Eagle XG Corning glass substrates (strain point 669 °C) using the LB method with the help of a KSV NIMA instrument (scheme Figure 1b). The size of the glass substrates (hereafter named GS) was 10 × 15 mm 2 , with a thickness of 0.5 mm.…”

Transfer of Epitaxial SrTiO3 Nanothick Layers Using Water-Soluble Sacrificial Perovskite Oxides

“…These nanosheets are deposited onto the substrates by Langmuir-like deposition using soft chemistry and the most common one is Ca 2 Nb 3 O 10 -. [25][26][27][28][29][30][31][32][33] These nanosheets are 2D materials, with a thickness of 1 to 2 nm and in-plane length from 500 nm to a few micrometers. The in-plane lattice parameter is 0.386 nm, close to the targeted perovskite used.…”