The temperature behavior of the crystal structure as well as dielectric and magnetic properties of the perovskite bismuth chromate ceramics with the 10 mol % Cr³⁺-to-Sc³⁺ substitution were studied and compared with those of the unmodified compound. Using a high-pressure synthesis, BiCrO₃ and BiCr_0.9Sc_0.1O₃ were obtained as metastable perovskite phases which are monoclinic C2/c with the √6a_p × √2a_p × √6a_p superstructure (where a_p is the primitive perovskite unit-cell parameter) under ambient conditions. At room temperature, the unit cell volume of BiCr_0.9Sc_0.1O₃ is ∼1.3% larger than that of BiCrO₃. Both perovskites undergo a reversible structural transition into a nonpolar GdFeO₃-type phase (orthorhombic Pnma, √2a_p × 2a_p × √2a_p) in the temperature ranges of 410–420 K (BiCrO₃) and 470–520 K (BiCr_0.9Sc_0.1O₃) with a relative jump of the primitive perovskite unit cell volume of about −1.6 and −2.0%, respectively. Temperature dependences of the complex dielectric permittivity demonstrate anomalies in the phase transition ranges. The Pnma-to-C2/c crossover in BiCrO₃ is accompanied by a decrease in the direct current (dc) conductivity, while in BiCr_0.9Sc_0.1O₃ the conductivity increases. The onset of an antiferromagnetic order in BiCr_0.9Sc_0.1O₃ is observed at the Néel temperature (T_N) of about 85 K as compared with T_N = 110 K in BiCrO₃. In contrast to BiCrO₃, which exhibits a spin reorientation at T_sr ∼ 72 K, no such a transition occurs in BiCr_0.9Sc_0.1O₃.

中文翻译：

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亚稳钙钛矿多铁型BiCrO3和BiCr0.9Sc0.1O3中的相变：比较研究。

研究了用10 mol％Cr ³⁺ -Sc ³⁺取代的钙钛矿型铬酸铋铋酸盐陶瓷的晶体结构的温度行为以及介电和磁性能，并与未改性化合物进行了比较。使用高压合成，BiCrO ₃和BiCr _0.9钪_0.1 ø ₃分别得到其是单斜晶钙钛矿型的亚稳相Ç 2 / ç与√6一个_p ×√2一个_p ×√6一个_p上层建筑（其中一个_p是在环境条件下原始的钙钛矿晶胞参数）。在室温下，BiCr _0.9 Sc _0.1 O ₃的晶胞体积比BiCrO _3的晶胞体积大约1.3％。既钙钛矿经历可逆结构转变成非极性GdFeO ₃型相（斜方晶系晶Pnma，√2一个_p ×2一个_p ×√2一个_p在410-420 K（BiCrO的温度范围）₃）和470-520钾（BiCr _0.9 Sc _0.1 O ₃），原始钙钛矿晶胞体积的相对跳跃分别约为-1.6％和-2.0％。复介电常数的温度依赖性证明在相变范围内存在异常。所述晶Pnma -到- c ^ 2 / ç在BiCrO交叉₃伴随在直流（dc）导电性降低，而在BiCr _0.9钪_0.1 ø ₃的导电性增加。与T _N相比，在Néel温度（T _N）约为85 K时，观察到BiCr _0.9 Sc _0.1 O _3中反铁磁有序的发生。在BiCrO _3中＝ 110K 。在对比BiCrO ₃，其在表现出自旋再取向Ť _SR〜72 K，没有这样的转变发生在BiCr _0.9钪_0.1 ø ₃。