Sequential two-stage displacive transformation from β to α via β′ phase in polymorphic MnTe film

Electrical Conduction Mechanism of β‐MnTe Thin Film with Wurtzite‐Type Structure Using Radiofrequency Magnetron Sputtering

“…[14,[19][20][21] Recently, we demonstrated that radiofrequency (RF) magnetron sputtering on a thermally oxidized SiO 2 substrate without intentional substrate heating can provide a β-phase even at room temperature. [7,17,18] The metastable β-MnTe film with WZ structure shows a p-type conduction and possesses the E g of 2.5 eV, [7,17,18] which is very similar to the reported value. [14] It has also been reported that the β-MnTe film has a high resistivity of over 10 3 Ω cm order, whereas the α-MnTe has a low resistivity of about 10 À1 Ω cm order, [7,15] indicating that there is an extremely large difference in resistivity between the αand β-MnTe films.…”

“…The obtained Brag reflection peaks are derived from α-W and β-W, which is similar to the reported XRD pattern of the W film on SiO 2 layer. [24] The result indicates that the films have the β-phase with a hexagonal wurtzite structure., [7,17] where the Bragg reflection peak at around 40 is mainly derived from the W layer. The Bragg reflection peaks of the β-MnTe film are broad, indicating fine grain size and poor crystallinity, which is due to the room-temperature-sputtering process without intentional substrate heating.…”

“…[8] Particularly, the α-MnTe, which exists in equilibrium at room temperature, has been intensively studied because it is expected to be used in many fields, such as dilute magnetic semiconductors, [9][10][11] thermoelectric material, [12,13] optoelectronic applications, [14][15][16] and PCMs. [7,17,18] Meanwhile, the β-MnTe has been very little studied because it is a high-temperature stable phase. Recently, it has been reported that the β-MnTe could be stabilized to room temperature through the nonequilibrium methods, such as the following techniques: depositing on an amorphous indium zinc oxide substrate, [19] using a ZnTe seed layer with substrate heating, [14] or alloying with ZnTe.…”

Photoinduced Nonvolatile Displacive Transformation and Optical Switching in MnTe Semiconductors

“…These images provide a clearer visualization of the crystal structures of βand α-MnTe than that in Figure 5b. Both images satisfy the crystallographic relationship between the wurtzite-and NiAs-type structures ((001 7 The findings in Figure 5c−e indicate that the photoinduced β → α transformation in this study occurs via atomic displacements, which does not require drastic structural changes or atomic diffusion. Furthermore, this process proceeded via first-order like nucleation and domain growth process as in other materials.…”

Recent Advances in Manganese-Based Materials for Electrolytic Water Splitting

“…The author confirmed this view and compared the products at different temperatures and found that the overpotential of α-MnS in the steady-state structure was 292 mV [ 60 ]. Mori et al carried out two consecutive phases of displacement transformation from β to α for MnTe with various phase states through the β′ phase; observed its induction process, transition direction, and binding force; and analyzed phase engineering from the ultra-micro perspective [ 108 ].…”