Role of precursor composition in the polymorph transformations, morphology control and ferromagnetic properties of nanosized TiO$_2$

TL;DR

This study investigates how precursor composition affects the polymorph, morphology, and ferromagnetic properties of nanosized TiO$_2$ synthesized via pyrolysis, revealing room temperature ferromagnetism in high-quality nanoparticles.

Contribution

It demonstrates that a carboxylate precursor can produce impurity-free, monodisperse TiO$_2$ nanoparticles with controllable properties, offering an alternative to sol-gel methods.

Findings

Produced 7-27 nm monodisperse TiO$_2$ nanoparticles.

Nanoparticles exhibit room temperature ferromagnetism.

Carboxylate precursor yields high-quality, impurity-free nanoparticles.

Abstract

Pure phase and mixed phase TiO$_2$ nanoparticles have been produced using a pyrolytic method from a non-aqueous carboxylate precursor. The precursor was prepared by a multiphase cation exchange using pentanoic acid (C$_4$H$_9$COOH). The thermal stability, polymorph content, morphology, size distribution and surface region of the produced nanoparticles were studied by TGA/DSC, XRD, FTIR and TEM. High quality monodisperse nanoparticles have been produced in the size range from 7 to 27 nm. The nanoparticles showed room temperature ferromagnetism revealed by VSM within bound polaron model. The carboxylate precursor is a good alternative to standard sol-gel to produce nanoparticles free from impurities.