Abstract

The physical properties of the NiB₄O₇ and CoB₄O₇ tetraborate compounds in three structural modifications with the sp. gr. Pbca, Cmcm, and P6₅22 have been calculated using the density functional theory in the VASP software package. The pressure dependences of the enthalpy of the compounds in the investigated structural modifications have been calculated. The calculated electron densities of states and band structures showed that the compounds under study in all the considered modifications are dielectrics with a band gap of 3–4 eV. The calculation of the magnetic exchange constants in the Heisenberg model have shown qualitative agreement with the experiment.

中文翻译：

---

四结构的四硼酸盐NiB 4 O 7和CoB 4 O 7的磁，电和光学性质

摘要

NiB ₄ O ₇和CoB ₄ O ₇四硼酸盐化合物的物理性质与sp的三个结构修饰。gr。Pbca，Cmcm和P 6 ₅使用VASP软件包中的密度泛函理论已计算出22。已经计算出所研究的结构修饰中化合物焓的压力依赖性。计算得到的态和能带结构的电子密度表明，在所有考虑的修饰中，所研究的化合物均为带隙为3-4 eV的电介质。海森堡模型中的磁交换常数的计算与实验表明了定性的一致性。