The solubility of transition metal oxides in zinc oxide and the reflectance spectra of Mn2+ and Fe2+ in tetrahedral fields

Design of Semiconducting TetrahedralMn1−xZnxOAlloys and Their Application to Solar Water Splitting

“…1(b), the temperature vs. composition phase diagram (binodal curve) is shown as determined from the standard common tangent construction in the freeenergy ΔGðxÞ ¼ ΔHðxÞ − TSðxÞ diagram, using the configurational entropy S ¼ −k B ½xlnðxÞ þ ð1 − xÞlnð1 − xÞ of the random alloy. The finding of a wide and asymmetric miscibility gap, with a larger Mn solubility in ZnO and a smaller Zn solubility in MnO, agrees with experimental solubility measurements [14]. Above 600°C, the calculated solubilities are, however, smaller than those determined in Ref.…”

“…Above 600°C, the calculated solubilities are, however, smaller than those determined in Ref. [14] at respective temperatures. We note that vibrational entropy contributions, not considered here, often increase the solubility at higher temperatures [19].…”

“…However, there are no experimental reports of alloys in the Mn-rich composition range, where the structural transition between the octahedral rocksalt structure (MnO ground state) and the tetrahedral wurtzite structure (ZnO ground state) is expected [11], and previous theoretical investigations for such alloys were restricted to the RS structure [12,13]. The alloy composition range of interest lies inside the miscibility gap [14], and the properties of such alloys are unknown.…”

Characterization of Manganese doped ZnO (MZO) thin films by Spin Coating Technique

“…In DMSs, transition metal doped II-VI and III-V semiconductors have been studied extensively [1]. One of the materials at the focus of much attention is the wide band gap wurtzite phase zinc oxide, a II-VI semiconductor, a well-known piezoelectric and electro-optic material with wide direct band gap (~3.37eV) and large exciton binding energy (60 meV) in which some of the zinc can be substituted by the manganese ions responsible for the ferromagnetic coupling [2,3].ZnO doped with Mn has also been considered as an ideal material for short wavelength magneto-optical applications due to its wide band gap and the thermal solubility of Mn in ZnO [4].Since the ionic radius of Mg 2+ (0.57 Å) is similar to that of Zn 2+ (0.60 Å), the latter can be substituted by the Mg 2+ ion resulting in a wide range of solid solution [5]. However, the thermo dynamic solubility limit of MgO in ZnO is only about 4% as suggested by the phase diagram of MgO-ZnO binary system [6].…”

Coherent diffractive imaging of solid state reactions in zinc oxide crystals

“…A dramatic increase in exposure time from 0.1 to 2 s was required to obtain the same level of statistics and the need for a wider rocking curve confirms a solid state chemical reaction between Fe and ZnO has taken place on a relatively large scale. The reaction proceeds at a relatively low temperature of 350 • C considering Bates et al [2] observed a solubility of zero at 500…”