Thermoelectric performance in the layered Zintl phase n-type Mg (Sb,Bi) is reported. Insertion of the excess Mg into the compounds is crucial for realizing n-type carrier transport with multivalley and isotropic character. An excellent ZT of 1.51 ± 0.06 at 716 K is achieved in the sintered polycrystals at the composition of Mg Sb Bi Te .

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The influence of grain boundaries is modelled to show that there is much room for improvement in some thermoelectric materials.

The electronic conduction through a Pr 0.7 Ca 0.3 MnO 3 thin film is investigated by measurements using dc and pulsed biases. Semiconducting Pr 0.7 Ca 0.3 MnO 3 films sandwiched by electrodes show both hysteretic and asymmetric behaviors in current-voltage characteristics. The observed conduction characteristics exhibit the spacecharge-limited-current effect, and the hysteretic behavior can be ascribed to a carrier trapping and detrapping of the trap sites in the manganite. The hysteresis induces a colossal electroresistance (CER) of more than 5000% at room temperature. The CER ratio is independent of the duration time of pulses from an infinite (dc) down to 150 ns, indicating that the carrier filling of all the traps can be completed within a short time.