Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer.
Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer.
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DOI：
10.1038/ncomms1361
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发表时间：
2011-06-14
影响因子：
16.6
通讯作者：
Attfield, J. Paul
中科院分区：
文献类型：
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作者：
Azuma, Masaki;Chen, Wei-tin;Seki, Hayato;Czapski, Michal;Olga, Smirnova;Oka, Kengo;Mizumaki, Masaichiro;Watanuki, Tetsu;Ishimatsu, Naoki;Kawamura, Naomi;Ishiwata, Shintaro;Tucker, Matthew G.;Shimakawa, Yuichi;Attfield, J. Paul
负热膨胀的不同寻常的性质是最重要的，可以用来制造零或其他受控热膨胀值的复合材料。在这里，我们报道了钙钛矿氧化物的巨大负热膨胀(定义为线性膨胀<；−10−4K−1，温度范围为~100K)，显示出电荷转移转变。BiNiO_3在加压下显示出2.6%的体积减小，这是由于通过La取代Bi而转移到常压下的Bi/Ni电荷转移。改变共存的低温和高温相的比例会导致加热时平滑的体积收缩。Bi0.95La0.05NiO3的线膨胀系数为−137×10−6K−1，在320~380K温度范围内测得−82×10−6 K−1。在环境条件下工作的巨大负热膨胀材料也可以通过铁电有序等其他现象驱动的金属-绝缘体转变而获得。负热膨胀-加热时收缩-是一种不寻常的过程，可以用来生产热膨胀值为零或其他受控的材料。Azuma等人。在BiNiO_3中观察到负热膨胀，这是Bi/Ni电荷转移转变的结果。
The unusual property of negative thermal expansion is of fundamental interest and may be used to fabricate composites with zero or other controlled thermal expansion values. Here we report that colossal negative thermal expansion (defined as linear expansion <−10−4 K−1 over a temperature range ~100 K) is accessible in perovskite oxides showing charge-transfer transitions. BiNiO3 shows a 2.6% volume reduction under pressure due to a Bi/Ni charge transfer that is shifted to ambient pressure through lanthanum substitution for Bi. Changing proportions of coexisting low- and high-temperature phases leads to smooth volume shrinkage on heating. The crystallographic linear expansion coefficient for Bi0.95La0.05NiO3 is −137×10−6 K−1 and a value of −82×10−6 K−1 is observed between 320 and 380 K from a dilatometric measurement on a ceramic pellet. Colossal negative thermal expansion materials operating at ambient conditions may also be accessible through metal-insulator transitions driven by other phenomena such as ferroelectric orders. Negative thermal expansion—contraction upon heating—is an unusual process that may be exploited to produce materials with zero or other controlled thermal expansion values. Azuma et al. observe negative thermal expansion in BiNiO3 which is a result of Bi/Ni charge-transfer transitions.
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影响因子：
16.6
作者：
Phillips, Anthony E.;Goodwin, Andrew L.;Kepert, Cameron J.
通讯作者：
Kepert, Cameron J.
影响因子：
4
作者：
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通讯作者：
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影响因子：
8.6
作者：
JAYARAMA.A;NARAYANA.V;MAINES, RG
通讯作者：
MAINES, RG
影响因子：
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作者：
Ishiwata, S;Azuma, M;Kato, K
通讯作者：
Kato, K
影响因子：
8.6
作者：
Belik, AA;Azuma, M;Takano, M
通讯作者：
Takano, M