No ferromagnetism in Mn doped ZnO semiconductors

Influence of Mn doping on the microstructure and optical property of ZnO

“…It has been observed earlier by other groups [13,14] that upon Mn doping in ZnO the band gap reduces for low concentration doping (< 3 mol% of Mn) and for higher concentration ( > 3 mol%) the band gap increases as expected on the basis of virtual crystal approximation (VCA) because of the band gap of the MnO ~ 4.2 eV. In many dilute magnetic semiconductor (DMS) systems such deviation from the linear monotonic increase in the form of "band gap bowing" has been observed [15][16][17][18][19][20][21] …”

Nanoparticles of ZnO Doped With Mn: Structural and Morphological Characteristics

“…The prediction 7 that p-type ZnO and GaN may exhibit ferromagnetism characteristic above room temperature in response to doping with Mn has initiated intensive experimental work on a variety of doped diluted magnetic semiconductors (DMS) [8][9][10][11][12][13][14] . Diluted magnetic semiconductors (DMSs), and particularly ferromagnetic oxides, are potential candidates for technological applications such as spin-transistors or the ultra-dense nonvolatile semiconductor memories 15 . This new field of semiconductor electronics controls and hence exploits the spin degree of freedom of the electron, in addition to or in place of its charge, for several applications.…”

Peculiarly strong room-temperature ferromagnetism from low Mn-doping in ZnO grown by molecular beam epitaxy

“…19 Original predictions based on the p-d Zender model required very high p-type doping for MnZnO to be a room temperature DMS, 5 which is very challenging to fulfill. Nevertheless many different types of behavior have been reported with MnZnO, such as being non-magnetic, 7 paramagnetic, 13 ferromagnetic, 8,17,18 antiferromagnetic, 20 and spin-glass like, 14 with no evident instance of the required heavy p-type doping. Other theories based on bound magnetic polarons (BMP), 21,22 F centers, 23 etc.…”

“…4 Transition metal (TM) doped ZnO materials are expected to have Curie temperatures above 300K, 1, 5 which led to a surge in research activities. Extensive work has been performed on synthesizing TM doped ZnO using various methods, including chemical reaction, 6,7 sintering, 8,9 ion implantation, [10][11][12] sputtering, 13 pulsed laser deposition, 14 metal-organic chemical vapor deposition 15 and molecular beam epitaxy (MBE). [16][17][18] Among these methods, MBE provides high quality thin films and precise doping profiles.…”