Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered Manganites
Double-layered manganites are natural superlattices with low thermal conductivity, which is of importance for potential thermoelectric applications. The Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub>...
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| author | Nailing Qin Yehai Pang Zhengbing Xu Xiyong Chen Jialin Yan |
| author_facet | Nailing Qin Yehai Pang Zhengbing Xu Xiyong Chen Jialin Yan |
| author_sort | Nailing Qin |
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| description | Double-layered manganites are natural superlattices with low thermal conductivity, which is of importance for potential thermoelectric applications. The Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> (<i>x</i> = 0.5; 0.625; 0.75) were prepared by the solid-state reaction method. All the samples crystallize in the tetragonal I4/mmm Sr<sub>3</sub>Ti<sub>2</sub>O<sub>7</sub> type structure. The unit cell volume and the distortion in the MnO<sub>6</sub> octahedra increase with increasing Gd content. Their thermoelectric properties were investigated between 300 and 1200 K. All exhibit an <i>n</i>-type semiconducting behavior. The electrical conductivity (<i>σ</i>) increases while the absolute value of the Seebeck coefficient (|<i>S</i>|) decreases with increasing Gd content. Simultaneous increases in <i>σ</i> and |<i>S</i>| with increasing temperature are observed at temperatures approximately higher than 600 K, and the power factor reaches a maximum value of 18.36 μW/(m K²) for <i>x</i> = 0.75 at 1200 K. The thermal conductivity (<i>κ</i>) is lower than 2 W/(m K) over the temperature range of 300–1000 K for all the samples and a maximum dimensionless figure of merit <i>ZT</i> of 0.01 is obtained for <i>x</i> = 0.75 at 1000 K. |
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| spelling | doaj.art-02aa9c6043334a6faf66f881e7726e3e2023-11-17T17:01:34ZengMDPI AGMaterials1996-19442023-03-01167254810.3390/ma16072548Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered ManganitesNailing Qin0Yehai Pang1Zhengbing Xu2Xiyong Chen3Jialin Yan4School of Resources, Environment and Materials, Guangxi University, Nanning 530004, ChinaSchool of Resources, Environment and Materials, Guangxi University, Nanning 530004, ChinaSchool of Resources, Environment and Materials, Guangxi University, Nanning 530004, ChinaSchool of Resources, Environment and Materials, Guangxi University, Nanning 530004, ChinaSchool of Resources, Environment and Materials, Guangxi University, Nanning 530004, ChinaDouble-layered manganites are natural superlattices with low thermal conductivity, which is of importance for potential thermoelectric applications. The Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> (<i>x</i> = 0.5; 0.625; 0.75) were prepared by the solid-state reaction method. All the samples crystallize in the tetragonal I4/mmm Sr<sub>3</sub>Ti<sub>2</sub>O<sub>7</sub> type structure. The unit cell volume and the distortion in the MnO<sub>6</sub> octahedra increase with increasing Gd content. Their thermoelectric properties were investigated between 300 and 1200 K. All exhibit an <i>n</i>-type semiconducting behavior. The electrical conductivity (<i>σ</i>) increases while the absolute value of the Seebeck coefficient (|<i>S</i>|) decreases with increasing Gd content. Simultaneous increases in <i>σ</i> and |<i>S</i>| with increasing temperature are observed at temperatures approximately higher than 600 K, and the power factor reaches a maximum value of 18.36 μW/(m K²) for <i>x</i> = 0.75 at 1200 K. The thermal conductivity (<i>κ</i>) is lower than 2 W/(m K) over the temperature range of 300–1000 K for all the samples and a maximum dimensionless figure of merit <i>ZT</i> of 0.01 is obtained for <i>x</i> = 0.75 at 1000 K.https://www.mdpi.com/1996-1944/16/7/2548double-layered manganitescrystal structurethermoelectric properties<i>n</i>-type perovskite oxides |
| spellingShingle | Nailing Qin Yehai Pang Zhengbing Xu Xiyong Chen Jialin Yan Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered Manganites Materials double-layered manganites crystal structure thermoelectric properties <i>n</i>-type perovskite oxides |
| title | Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered Manganites |
| title_full | Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered Manganites |
| title_fullStr | Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered Manganites |
| title_full_unstemmed | Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered Manganites |
| title_short | Structural and Thermoelectric Properties of Gd<sub>2−2<i>x</i></sub>Sr<sub>1+2<i>x</i></sub>Mn<sub>2</sub>O<sub>7</sub> Double-Layered Manganites |
| title_sort | structural and thermoelectric properties of gd sub 2 2 i x i sub sr sub 1 2 i x i sub mn sub 2 sub o sub 7 sub double layered manganites |
| topic | double-layered manganites crystal structure thermoelectric properties <i>n</i>-type perovskite oxides |
| url | https://www.mdpi.com/1996-1944/16/7/2548 |
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