The Combination of Colloid‐Controlled Heterogeneous Nucleation and Polymer‐Controlled Crystallization: Facile Synthesis of Separated, Uniform High‐Aspect‐Ratio Single‐Crystalline BaCrO4 Nanofibers

Uniform, separated BaCrO4 single‐crystalline nanofibers with high aspect ratio (> 5000, see Figure) can be fabricated at room temperature in aqueous solution using a double hydrophilic block copolymer as structure‐directing agent and introducing colloidal nucleation agents. Such fibers represent a model case for advanced polymer fillers and the exploration of quasi‐1D nanostructures with interesting electrical, optical, or catalytic properties.