Synthesis and Characterization of Tungsten Suboxide W<sub>n</sub>O<sub>3n−1</sub> Nanotiles

oleh: Luka Pirker, Bojana Višić, Janez Kovač, Srečo D. Škapin, Maja Remškar

Format: Article
Diterbitkan: MDPI AG 2021-08-01

Deskripsi

W<sub>n</sub>O<sub>3n−1</sub> nanotiles, with multiple stoichiometries within one nanotile, were synthesized via the chemical vapour transport method. They grow along the [010] crystallographic axis, with the thickness ranging from a few tens to a few hundreds of nm, with the lateral size up to several µm. Distinct surface corrugations, up to a few 10 nm deep appear during growth. The {102}<sub>r</sub> crystallographic shear planes indicate the W<sub>n</sub>O<sub>3n−1</sub> stoichiometries. Within a single nanotile, six stoichiometries were detected, namely W<sub>16</sub>O<sub>47</sub> (WO<sub>2.938</sub>), W<sub>15</sub>O<sub>44</sub> (WO<sub>2.933</sub>), W<sub>14</sub>O<sub>41</sub> (WO<sub>2.928</sub>), W<sub>13</sub>O<sub>38</sub> (WO<sub>2.923</sub>), W<sub>12</sub>O<sub>35</sub> (WO<sub>2.917</sub>), and W<sub>11</sub>O<sub>32</sub> (WO<sub>2.909</sub>), with the last three never being reported before. The existence of oxygen vacancies within the crystallographic shear planes resulted in the observed non-zero density of states at the Fermi energy.