Recent research shows that increasing the carrier density after orbital alignment in AZn_(2)Sb_(2) (A=Ca,Yb,Eu,Sr,Mg)Zintl compounds yields remarkable results with regard to enhanced thermoelectric performance.However...Recent research shows that increasing the carrier density after orbital alignment in AZn_(2)Sb_(2) (A=Ca,Yb,Eu,Sr,Mg)Zintl compounds yields remarkable results with regard to enhanced thermoelectric performance.However,research on carrier density increase via doping in these compounds is limited.In this study,we introduced Cu into the Zn sites in YbZn_(2)Sb_(2) and examined the thermoelectric properties.展开更多
In this work,we show significantly enhanced thermoelectric performance in Cu_(2) SnSe_(3) via a synergistic effect of Cd-doping and CuGaTe_(2) alloying in the temperature range of 300-823 K.Both the electron and phono...In this work,we show significantly enhanced thermoelectric performance in Cu_(2) SnSe_(3) via a synergistic effect of Cd-doping and CuGaTe_(2) alloying in the temperature range of 300-823 K.Both the electron and phonon transport properties can be simultaneously regulated by Cd doping at Sn site,leading to a higher quality factor.Meanwhile,a maximum figure of merit(zT) value of ~0.68 was obtained for Cu_(2) Sn_(0.93)Cd_(0.07)Se_(3) sample at823 K,which is about four times higher than that of the pristine sample(zT=0.18 at 773 K).Furthermore,Cu_(2) Sn_(0.93)Cd_(0.07)Se_(3) was alloyed with CuGaTe_(2) to reduce the lattice thermal conductivity in the high-temperature region.Consequently,a further enhanced zT value(0.77,823 K) was achieved in the(Cu_(2) Sn_(0.93)Cd_(0.07)Se_(3))_(0.94)(CuGaTe_(2))_(0.06) sample,with a high average zT(zT_(ave)) value of0.30 between 300 and 823 K.These results demonstrate that Cd-doping combined with CuGaTe2 alloying could be an effective method to enhance zT values of Cu_(2) SnSe_(3) based compounds.展开更多
Bi_(0.85)La_(0.15)FeO_(3)(BLFO)nanotubes with an average diameter of about 200 nm and wall thickness of about 20 nm are fabricated by solgel alumina template technique,and their room-temperature multiferroic properti...Bi_(0.85)La_(0.15)FeO_(3)(BLFO)nanotubes with an average diameter of about 200 nm and wall thickness of about 20 nm are fabricated by solgel alumina template technique,and their room-temperature multiferroic properties are studied.Piezoelectricity and ferroelectricity in the BLFO nanotubes are revealed by piezoresponse force microscopy study of individual nanotube.Doping the BiFeO_(3)nanotubes with La reduces the crystallization temperature and results in a reduced lose of Bi and therefore improved multiferroic properties of the nanotubes.Enhanced weak ferromagnetism is also observed,and it is attributed to the nano-crystalline structure of the nanotubes.展开更多
基金financially supported by the National Natural Science Fund for Distinguished Young Scholars(No.52125103)the National Natural Science Foundation of China(Nos.11904039 and 52071041)+1 种基金the Scientific Research Project of Hubei Provincial Department of Education(No.B2021134)Hubei Provincial Natural Science Foundation of China(No.2023AFB924)。
文摘Recent research shows that increasing the carrier density after orbital alignment in AZn_(2)Sb_(2) (A=Ca,Yb,Eu,Sr,Mg)Zintl compounds yields remarkable results with regard to enhanced thermoelectric performance.However,research on carrier density increase via doping in these compounds is limited.In this study,we introduced Cu into the Zn sites in YbZn_(2)Sb_(2) and examined the thermoelectric properties.
基金financially supported by the National Natural Science Foundation of China (Nos.11874356, 52071041,12004060,51972102 and 51877023)the Key Research Program of Frontier Sciences,CAS (No.QYZDB-SSW-SLH016)。
文摘In this work,we show significantly enhanced thermoelectric performance in Cu_(2) SnSe_(3) via a synergistic effect of Cd-doping and CuGaTe_(2) alloying in the temperature range of 300-823 K.Both the electron and phonon transport properties can be simultaneously regulated by Cd doping at Sn site,leading to a higher quality factor.Meanwhile,a maximum figure of merit(zT) value of ~0.68 was obtained for Cu_(2) Sn_(0.93)Cd_(0.07)Se_(3) sample at823 K,which is about four times higher than that of the pristine sample(zT=0.18 at 773 K).Furthermore,Cu_(2) Sn_(0.93)Cd_(0.07)Se_(3) was alloyed with CuGaTe_(2) to reduce the lattice thermal conductivity in the high-temperature region.Consequently,a further enhanced zT value(0.77,823 K) was achieved in the(Cu_(2) Sn_(0.93)Cd_(0.07)Se_(3))_(0.94)(CuGaTe_(2))_(0.06) sample,with a high average zT(zT_(ave)) value of0.30 between 300 and 823 K.These results demonstrate that Cd-doping combined with CuGaTe2 alloying could be an effective method to enhance zT values of Cu_(2) SnSe_(3) based compounds.
基金supported by the Hong Kong RGF grant(No.BQ-994)the National Science Foundation of China(NSFC)(Grant Nos.90923013,50902046).
文摘Bi_(0.85)La_(0.15)FeO_(3)(BLFO)nanotubes with an average diameter of about 200 nm and wall thickness of about 20 nm are fabricated by solgel alumina template technique,and their room-temperature multiferroic properties are studied.Piezoelectricity and ferroelectricity in the BLFO nanotubes are revealed by piezoresponse force microscopy study of individual nanotube.Doping the BiFeO_(3)nanotubes with La reduces the crystallization temperature and results in a reduced lose of Bi and therefore improved multiferroic properties of the nanotubes.Enhanced weak ferromagnetism is also observed,and it is attributed to the nano-crystalline structure of the nanotubes.
