The results of the first experimental studies on the structural (lattice parameters) and elastic characteristics of ErBaCo₄O_{7 + x} cobaltites in the range of structural and magnetic phase transitions are presented. The samples obtained using different thermal treatments and characterized by a small oxygen excess x are studied. It is found that the parameter Δa/a for the stoichiometric ErBaCo₄O₇ sample annealed in vacuum exhibits no anomalies in the course of a structural transition, whereas the parameters b and c undergo stepwise changes of opposite signs. The different values of these changes Δb/b ≈ 4 × 10⁻³ and Δc/c ≈ −5 × 10⁻³ result in the stepwise volume change ΔV/V ≈ −10⁻³. A slight deviation from the oxygen stoichiometry affects the character of the structural distortion; namely, the magnitude of the anisotropic strain and the sign of the isotropic strain change. The structural distortion in the stoichiometric sample is accompanied by a sharp stepwise change in the Young’s modulus ΔE(T)/E₀ ∼ 8 × 10⁻², whereas the magnitude of elastic anomalies near T_S in slightly nonstoichiometric samples with x ∼ 0.03 decreases by an order of magnitude. Comparison of elastic anomalies manifesting themselves near the magnetic phase transition temperature T_N for distorted samples with different deviations from stoichiometry suggests that the arising long-range magnetic order in the cobalt subsystem is apparently affected not only by structural distortions but also by disorder introduced by nonstoichiometric oxygen.

给出了关于在结构和磁性相变范围内ErBaCo ₄ O _{7 + x}钴的结构（晶格参数）和弹性特性的首次实验研究的结果。研究了使用不同热处理方法获得的样品，这些样品的特征在于氧过量x较小。发现在真空中退火的化学计量的ErBaCo ₄ O ₇样品的参数Δa / a在结构转变过程中没有表现出异常，而参数b和c经历了相反符号的逐步变化。这些变化的不同值Δb / b≈4×10 ^-3和Δc / c≈-5×10 ^-3导致逐步的体积变化ΔV / V≈-10 ^-3。氧化学计量的轻微偏差会影响结构变形的特性；即，各向异性应变的大小和各向同性应变的符号变化。化学计量样品中的结构变形是伴随着在杨氏模量Δ的急剧逐步变化ë（Ť /）Ê ₀〜8×10 ^-2，而邻近弹性异常的大小Ť_小号具有略微非化学计量的样品中的X〜0.03减小一个数量级。对于与化学计量学有不同偏差的变形样品，在磁相变温度T _N附近表现出的弹性异常的比较表明，钴子系统中出现的远距离磁序显然不仅受到结构变形的影响，而且还受到非化学计量学引入的无序性的影响氧。