Preparation of Ni-doped ZnO ceramics for thermoelectric applications

Fabrication and thermoelectric properties of CuMn1+xO2 (x=0~0.2) ceramics

“…The S value of the x¼ 0.143 sample is higher than those of the other samples. The highest value at 573 K was 550 μV/K, which is similar to the values for CuMnO 2 reported by Koriche et al [24] and Trai et al [33], and higher than those reported for undoped Ca 3 Co 4 O 9 , SrTiO 3 , and ZnO samples [30][31][32].…”

“…An increase in the value of x leads to a decrease in thermal conductivity, because it causes the secondary phase to disappear and a complete layer structure to develop. At 573 K, the lowest value of thermal conductivity for the x¼ 0.1 sample was 6.79 W m À 1 K À 1 , which is between the values obtained for Ca 3 Co 4 O 9 , SrTiO 3 , and ZnO samples [30][31][32]. The trend of thermal conductivity for the CuMn 1 þ x O 2 (0r x r 0.2) samples is similar, because the main phase of all samples is CuMnO 2 with a delafossite structure.…”

“…At 573 K, the electrical conductivity for the x=0 sample had the highest value (0.11 S/cm), which is four orders of magnitude higher than that obtained at room temperature. Nevertheless, this value (0.11 S/cm) is smaller than those reported for undoped Ca 3 Co 4 O 9 , SrTiO 3 , and ZnO samples, which range from about 0.5 to 80 S/cm at 573 K [30][31][32]. The plots of (αhν) 2 , the square of the absorption coefficient (α) multiplied by the photon energy (hν), versus photon energy, are shown in Fig.…”

Formation of ZnO/Ni_0.6Zn_0.4O Mixture Using Mechanical Milling of Zn-NiO

“…4) Physical, magnetic and optical properties of Ni-doped ZnO and Ni x Zn 1-x O solid solutions synthesized by addition of NiO (0-2.0 mol%) to ZnO is reported by different research teams. 1,[4][5][6][7][8] High energy mechanical milling and mechanochemical processes are, on the other hand, considered as simple and cost-effective techniques employed for preparation of nano-sized and nonocrystalline materials which can induce chemical reactions that do not normally happen at room temperature. [9][10][11][12] Mechanochamical reactions have been the subject of investigations on displacement reactions between metal compounds and a reducing metal.…”

A review of thermoelectric ZnO nanostructured ceramics for energy recovery

“…Among the thermoelectric materials, zinc oxide displays a good seebeck coefficient value, a high thermal stable temperature ranges and low environmental impact [22,23]. The different investigations on ZnO materials present that their thermoelectric properties can be improved by substitution with different element such as Aluminum [1][2][3][4][24][25][26][27][28], Cerium and Dysprosium [29], Gallium [6,[30][31][32], Indium [33], praseodymium [34], Antimony [20] and Nickel [7,19]. Therefore, ZnO as thermoelectric materials is slowly developing, but surely gaining attention as one of the candidates for thermoelectric applications.…”