Capturing Phase Evolution during Solvothermal Synthesis of Metastable Cu₄O₃

Abstract

The metastability of Cu4O3 has long hindered the synthetic preparation of bulk samples with substantial crystallinity. The lack of suitable samples has thwarted the detailed understanding of the magnetic properties of Cu4O3 and the ability to tune its properties. While Cu4O3 was recently shown to form in solvothermal reactions, the results are unpredictable, and the crystals are small. We developed a new, more uniform synthesis technique using sealed fused silica tubes. Interrogation of the solid and liquid phases resulting from this reaction has shed more light on the kinetic evolution of copper-containing phases and the microstructural correlation between different precipitation products. We find that direct conversion of the intermediate phase Cu2(NO3)­(OH)3 to Cu4O3 is a likely consequence of dimethylformamide (DMF) triggered in situ reduction. The optimal reduction environment should be more straightforward to attain given the improved reliability of our method, and it remains under investigation. We verify the formation of Cu4O3 via X-ray diffraction, Raman microscopy, and SQUID magnetometry.

Structure‐Selective Cation Exchange in the Synthesis of Zincblende MnS and CoS Nanocrystals

“…Such synthetic strategies make it possible to avoid undesired phases that most readily form while instead favoring the formation of alternate phases of the same composition. For example, solid‐state metathesis, topotactic transformations, epitaxial thin film formation, and solvothermal precipitation methods have succeeded in producing phases having crystal structures that cannot be accessed directly through traditional high temperature reactions.…”

“…A foundational goal of materials synthesis is the ability to predictably access atargeted crystal structure,asthe arrangements and coordination environments of the constituent atoms help to define its properties.I ti se specially important to identify synthetic pathways that lead to the formation of crystal structures that are metastable in bulk systems,a nd therefore not typically accessible.S uch synthetic strategies make it possible to avoid undesired phases that most readily form while instead favoring the formation of alternate phases of the same composition. Fore xample,s olid-state metathesis, [1][2][3] topotactic transformations, [4][5][6] epitaxial thin film formation, [7][8][9] and solvothermal precipitation methods [10][11][12][13][14][15] have succeeded in producing phases having crystal structures that cannot be accessed directly through traditional high temperature reactions.…”

Biosynthesis of Cu4O3 nanoparticles using Razma seeds: application to antibacterial and cytotoxicity activities

“…Cu 4 O 3 is a p-type semiconductor with a direct band gap of 2.34 eV and an indirect band gap of 1.50 eV [19]. The binary family of cuprous oxide (Cu 2 O), cupric oxide (CuO) and paramelaconite (Cu 4 O 3 ) has numerous functional applications due to their unique structures and electronic configurations [20]. Paramelaconite Cu 4 O 3 is a mineral that shows puzzling magnetic properties.…”

“…CuSO 4 was purchased from SD Fine Chemicals Ltd., Mumbai; Razma seeds were collected from a local supermarket in Tumkur. 20 grams collected Razma seeds was powdered using mixer grinder. The powder was added to 500-mL roundbottomed flask containing 400 mL of distilled water.…”

Structure‐Selective Cation Exchange in the Synthesis of Zincblende MnS and CoS Nanocrystals

“…Fore xample,s olid-state metathesis, [1][2][3] topotactic transformations, [4][5][6] epitaxial thin film formation, [7][8][9] and solvothermal precipitation methods [10][11][12][13][14][15] have succeeded in producing phases having crystal structures that cannot be accessed directly through traditional high temperature reactions. Fore xample,s olid-state metathesis, [1][2][3] topotactic transformations, [4][5][6] epitaxial thin film formation, [7][8][9] and solvothermal precipitation methods [10][11][12][13][14][15] have succeeded in producing phases having crystal structures that cannot be accessed directly through traditional high temperature reactions.…”