High-Throughput Selection and Experimental Realization of Two New Ce-Based Nitride Perovskites: CeMoN₃ and CeWN₃

Abstract

Nitride perovskites have only been experimentally realized in very few cases despite the widespread existence and commercial importance of perovskite materials. From oxide perovskites used in ultrasonics to halide perovskites that have revolutionized the photovoltaics industry, the discovery of new perovskite materials has historically impacted a wide number of fields. Here, we add two new perovskites, CeWN 3 and CeMoN 3 , to the list of experimentally realized perovskite nitrides using high-throughput computational screening and subsequent high-throughput thin film growth techniques. Candidate compositions are first down-selected using a tolerance factor and then thermochemical stability. A novel competing fluorite-family phase is identified for both material systems, which we hypothesize is a transient intermediate phase that crystallizes during the evolution from an amorphous material to a stable perovskite. Different processing routes to overcome the competing fluorite phase and obtain phase-pure nitride perovskites are demonstrated for the CeMoN 3– x and CeWN 3– x material systems, which provide a starting point for the development of future nitride perovskites. Additionally, we find that these new perovskite phases have interesting low-temperature magnetic behavior: CeMoN 3– x orders antiferromagnetically below T N ≈ 8 K with indications of strong magnetic frustration, while CeWN 3– x exhibits no long-range order down to T = 2 K but has strong antiferromagnetic correlations. This work demonstrates the importance and effectiveness of using high-throughput techniques, both computational and experimental: they are integral to optimize the process of realizing two entirely novel nitride perovskites.

Thermodynamic Stability and Anion Ordering of Perovskite Oxynitrides

“…We note the recent synthesis of some perovskite nitride materials with cation chemistries similar to those we predict to be stable in perovskite oxynitrides, specifically CeWN 3−x , CeMoN 3−x , and LaWN 3 perovskite nitrides. 43,44 Synthesis of these nitrides often involves thin-film deposition via sputtering in an atmosphere with high levels of reactive nitrogen or in the presence of N plasma in order to avoid the incorporation of O into the nitride lattice. Nevertheless, nitride crystals are known to release N anions from the lattice, which facilitates both Mars−van Krevelen reaction mechanisms and the deactivation of nitride electrocatalysts.…”

Local chemical origin of ferroelectric behavior in wurtzite nitrides

“…13–18 The race to develop new polar—and potentially ferroelectric—materials has seen significant recent expansion into nitride chemistries, most notably with the wurtzite and perovskite structures. 19–23…”

“…[13][14][15][16][17][18] The race to develop new polar-and potentially ferroelectric-materials has seen significant recent expansion into nitride chemistries, most notably with the wurtzite and perovskite structures. [19][20][21][22][23] Among nitride ferroelectrics, the wurtzite aluminum scandium nitride alloy (Al 1Àx Sc x N) ferroelectric has received significant attention because of its enhanced piezoelectric response, 24 robust ferroelectricity, 20 and compatibility with both Si and III-N semiconductor processes. Chemistry, stress, strain, and film thickness have been rigorously investigated to control ferroelectricity in this material system.…”

Can Nitride Perovskites Provide the Same Superior Optoelectronic Properties as Lead Halide Perovskites?

“…The first nitride perovskite TaThN 3 was reported in 1995 . Since then, several nitride perovskites have been theoretically predicted to be thermodynamically stable and exhibit large ferroelectric polarizations. − Since 2021, LaWN 3 , − LaReN 3 , CeMoN 3 , and CeWN 3 nitride perovskites have been experimentally synthesized one after another, which opens the door to the synthesis of more nitride (or other pnictides) perovskites.…”

“…At the chemical potential point E (i.e., the N-poor condition), as shown in Figure d, the formation enthalpy of V N is largely reduced. The easy formation of V N under the N-poor condition should explain the experimental observation that the synthesized nitride perovskites LaWN 3 , CeMoN 3 , and CeWN 3 were all N-deficient. , Under the N-poor condition, the E F,e is pushed up to 1.50 eV above the VBM, yielding a very weak n -type conductivity with a low electron density of 1.7 × 10 10 cm –3 . These results indicate that the electrical properties of LaWN 3 can hardly be tuned by adjusting the chemical synthesis condition.…”