Ferromagnetism in Cu-doped ZnO films: Role of charge carriers

Abstract

We report the observation of room temperature ferromagnetism in Cu-doped (5%) ZnO films grown on c-plane sapphire substrates. Films were prepared by pulsed laser deposition technique and were thoroughly characterized using several state-of-the-art characterization techniques. Hall measurements showed that the films are of n-type with a carrier concentration of 3×1017cm−3. Magnetization measurements showed that the films exhibit room temperature ferromagnetism with a saturation magnetization of ∼1.45μB∕Cu atom. When additional carriers were introduced in the films, ferromagnetism was completely vanished. Our results show that the p-type nature of the film is not essential for realizing ferromagnetic characteristics; however, the concentration of n-type carriers should not exceed a critical value.

On the Defect Origin of the Room‐Temperature Magnetism Universally Exhibited by Metal‐Oxide Nanoparticles

“…Synthesis of ZnO Nanoflowers and Thin Films at Liquid-Liquid Interfaces: Single-crystalline thin films and nanoflowers of ZnO were synthesized by the reaction of zinc cupferronate [Zn(cup) 2 ] with NaOH at the aqueous-organic interface. For preparing a singlecrystalline film of ZnO, NaOH (0.16 g) was dissolved in 25 mL of water (0.04 m) in a 100 mL beaker, and Zn(cup) 2 (1 mg) was dissolved in 25 mL of toluene.…”

Co-Precipitation Synthesis and Characterization of Nanocrystalline Zinc Oxide Particles Doped with Cu<sup>2+</sup> Ions

“…Motivated by these contradictory results, experimental studies have addressed the magnetic properties of Cu-doped, since it is known that the metallic Cu as well as all possible Cu-based oxide such as Cu 2 O or CuO is nonmagnetic [10]. Therefore, several scientists suggested that if any ferromagnetism is observed in Cu-based system, then it will undoubtedly be the intrinsic property of the material [11]. However, the experimental results still remain controversial; Buchholz et al [12] nonferromagnetism in n-type Cu-doped ZnO sample.…”

Magnetic and nonlinear optical properties of BaTiO3 nanoparticles

“…17,18 When the electron concentration crosses the critical value for the above system, the ferromagnetic interactions reduces. 19 Hence the p-d hybridization is crucial in describing the observed magnetism in the above systems. [20][21][22][23][24][25] The common feature for dilute magnetic semiconductors and defect based magnetism in oxide materials is the density of charge carriers.…”