A facile and environmentally friendly route to multiferroic nanorods and their size-dependent magnetic properties

Multiferroic ErMn₂O₅ nanorods have been synthesized via a surfactant-templated hydrothermal route. An environmentally friendly natural surfactant (Arabic gum) has been utilized as a template to prepare ErMn₂O₅ nanorods with a controllable morphology and size (i.e., nanorods with various lengths and basically invariable diameter). ErMn₂O₅ nanorods show strong size-dependent magnetic properties that correlate with: (a) a critical length for magnetization, and (b) recognizable divagation between FC and ZFC curves at low temperature. The former could be ascribed to the competition between surface strain and uncompensated spin at the surface, and the latter to Er antiferromagnetic ordering.