Ferromagnetic transition metal implanted ZnO: A diluted magnetic semiconductor?

Abstract

Recently theoretical works predict that some semiconductors (e.g. ZnO) doped with magnetic ions are diluted magnetic semiconductors (DMS). In DMS magnetic ions substitute cation sites of the host semiconductor and are coupled by free carriers resulting in ferromagnetism. One of the main obstacles in creating DMS materials is the formation of secondary phases because of the solid-solubility limit of magnetic ions in semiconductor host. In our study transition metal ions were implanted into ZnO single crystals with the peak concentrations of 0.5-10 at.%. We established a correlation between structural and magnetic properties. By synchrotron radiation X-ray diffraction (XRD) secondary phases

Spin-polarized electronic structure of the core–shell ZnO/ZnO:Mn nanowires probed by X-ray absorption and emission spectroscopy

“…As confirmed by X-ray diffraction 34 highpressure PLD process used in the experiment produces highquality Mn doping of ZnO, free of secondary phases (see Figure S3 in supplementary information). However, standard laboratory X-ray diffraction fails to detect small amounts of dopant-related secondary phases 35 and nanosized precipitations do not produce pronounced peaks in the diffraction pattern. For this reason, the Mn local atomic structure was investigated by Mn K-edge x-ray absorption fine structure.…”

“…S3 in ESI †). However, standard laboratory X-ray diffraction fails to detect small amounts of dopant-related secondary phases 35 and nanosized precipitations do not produce pronounced peaks in the diffraction pattern. For this reason, the Mn local atomic structure was investigated by Mn K-edge X-ray absorption ne structure.…”

Effect of substrate on structural and transport properties of sprayed Fe:ZnO polycrystalline thin films

“…Fe-doped ZnO (Fe:ZnO) film could be an important multi-functional material. Reports about Fe:ZnO thin films focus mostly on ferromagnetic properties [12][13][14][15][16]. Structural, optical, and electrical properties of Fe:ZnO films are relatively less studied [17][18][19] though it merit deeper understanding.…”

Ferromagnetism in Fe‐doped ZnO bulk samples with additional Cu doping

“…Following the original report by Ueda et al 12, many experiments have been carried out to confirm the theory prediction and the initial result. Some results dealing with RT FM of Fe‐doped ZnO samples have also been published 13–20. However, there remain some questions regarding the origin of the magnetic behavior in these DMS materials.…”

“…Contrarily, Shim et al 19 showed that RT FM in Fe‐doped ZnO with additional Cu doping stems from nanocrystalline ZnFe 2 O 4 with an inverted spinel structure. Zhou et al 20 reported that the metallic α‐Fe nanocrystals may be responsible to the FM in Fe‐implanted ZnO single‐crystal samples. A detailed structural, chemical bonding states, and magnetic investigation with high‐quality codoped samples is essential to resolve the controversy.…”