High-Throughput Synthesis and Characterization of (Ba_xSr_1–x)_1+yTi_1–yO_3−δ and (Ba_xSr_1–x)_1+yTi_1–yO_3–zN_z Perovskite Thin Films

Abstract

Thin films of (Ba x Sr 1−x ) 1+y Ti 1−y and Zr, Gd codoped (Ba x Sr 1−x ) 1+y Ti 1−y were deposited on platinized sapphire substrates at 640 °C under constant flux of atomic oxygen or a mixture of atomic oxygen and nitrogen to synthesize perovskites of (Ba x Sr 1−x ) 1+y Ti 1−y O 3−δ (also referred to as BSTO), (Ba x Sr 1−x ) 1+y Ti 1−y O 3−z N z (also referred to as BSTON), and Zr, Gd codoped (Ba x Sr 1−x ) 1+y Ti 1−y O 3−z N z . Structural characterization was done via XRD and XPS, and electrical characterization was done via LCR (dielectric properties and tunability under DC bias) and P−E measurements. Although the levels of nitrogen incorporated within the perovskite structure appear to be very low as determined by XPS analysis, definite improvements in dielectric properties and tunability have been achieved by synthesis of the BSTON oxynitride films. For a composition of Ba 0.8 Sr 0.2 TiO 3−z N z an improvement by a factor of 1.72 for tunability and 1.44 for relative permittivity has been observed between the oxide and the oxynitride. The oxynitride achieved a tunability ratio of 6.78 to 1 (close to 7:1) under an applied electrical field of 34 kV/mm. The high throughput approach allowed us to highlight a compositional shift for the material with the best dielectric properties when comparing the oxide with the oxynitride thin films. Effects of codoping the perovskite structure with Zr and Gd have also been investigated and although the tunability and dielectric constant of the thin films were not improved, some improvements in dielectric losses were observed, along with a superparaelectric state as observed by P−E hysteresis measurements.

Metal oxynitrides as emerging materials with photocatalytic and electronic properties

“…105 The dielectric constant of LaTiO 2 N films was 325 whereas in N doped Ba x Sr 1Àx TiO 3 films it improved by a factor of 1.44 with respect to the undoped material. 105 The dielectric constant of LaTiO 2 N films was 325 whereas in N doped Ba x Sr 1Àx TiO 3 films it improved by a factor of 1.44 with respect to the undoped material.…”

Combinatorial synthesis and screening of (Ba,Sr)(Ti,Mn)O3 thin films for optimization of tunable co-planar waveguides

“…34 The synthesis protocol is based on a slightly modified method as reported in more detail elsewhere. 4 Ba (Alfa Aesar: 99.9 %,) and Sr pieces (Alfa Aesar: 99 %), and Mn flakes (GoodFellow: 99.95%) were contained in Ta, PBN and Al2O3 crucibles respectively, and evaporated using Knudsen cells (from DCA instruments). Ti pellets (99.995 % supplied from Testbourne) were placed on a graphite crucible and evaporated with a 40 cc electron gun from Telemark.…”

“…Electrically tunable barium strontium titanate (BaxSr1-xTiO3) perovskite films, hereafter referred as BSTO, of the general stoichiometry ABO3 (A and B cations of different sizes) are of strong interest due to their appealing electrical properties. [1][2][3][4] As the films possess high relative permittivity r, low loss tangent BSTO investigated for dynamic random access memory (DRAM), 5 high voltage capacitors, 6 tunable filters 7 , microwave phase shifters 8,9 etc. Although semiconductors, liquid crystals, optical fibers, magnets, ceramics and ceramic nanocomposites 10 and many other alternative materials have been used for tunable devices, ferroelectrics in their paraelectric phase are far more effective, as they exhibit high dissipation factor (Q), consume negligible power, operate at high speeds and can be tuned with relatively low DC bias (<30 V).…”

“…There are many ways to deposit perovskite films with ABO3 structure, such as sputtering, 17 PLD, 30 Metal Organic Chemical Vapour Deposition (MOCVD), 31 sol-gel method 20 and Molecular Beam Epitaxy (MBE). 4,32,33 In this paper, a modified MBE system was used to synthesize the thin films. We report a systematic study of coplanar waveguide (CPW) structure microwave phase shifters with Mn doping BSTO ceramics.…”

Ammonothermal Synthesis of EAMO2N (EA = Sr, Ba; M = Nb, Ta) Perovskites and 14N Solid‐State NMR Spectroscopic Investigations of AM(O,N)3 (A = Ca, Sr, Ba, La)

“…Pulsed laser deposition for growth of thin films is challenging and product thickness of only several 100 nm or less is obtained. Apart from that, films possess high quality and crystallinity and atomically smooth surfaces that makes them suitable for the investigation of electronic properties . High‐pressure synthesis of oxonitride perovskites starting from R 2 O 3 ( R = Pr, Nd and Sm) with Zr 2 ON 2 typically requires a multianvil setup yielding only small amounts of the product.…”