Owing to its miniaturization and high dielectric permittivity, BaTiO-based multilayer ceramic capacitors (MLCCs) have attracted more and more attention in recent years, and are widely used in gamma-ray environments, such as nuclear and space application. Compared to the extensively studied thermal or electrical reliability issues, the potential risks caused by irradiation have not been well understood, let alone the dielectric structure changes. Unlike the common monotonic dose-dependent trend, we found non-monotonic results in MLCCs with low dose, named as the anomalous low dose (ALD) phenomenon. That is the capacitance decreases at low gamma-ray doses, and then abnormally recovers to the initial value at high doses. Similar cases have been found in almost all the physical properties of MLCCs. Intensive characterizations help to confirm that it is the dose-dependent consistent lattice and electronic structure changes that are most likely to cause this anomalous phenomenon. In detail, the gamma irradiation induces charged defects and consequently lattice distortion, which reduces the number of domains with low-field inversion and eventually causes the capacitance decrease. This work provides a new cognition about the gamma irradiation effect of BaTiO-based (BTO) dielectrics and commercial MLCCs based on BTO.

中文翻译：

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伽马辐照 BaTiO3 基商用多层陶瓷电容器中的异常低剂量现象

由于其小型化和高介电常数，BaTiO基多层陶瓷电容器（MLCC）近年来引起了越来越多的关注，并广泛应用于核和空间应用等伽马射线环境中。与广泛研究的热或电可靠性问题相比，辐照引起的潜在风险尚未得到很好的了解，更不用说介电结构的变化了。与常见的单调剂量依赖性趋势不同，我们在低剂量MLCC中发现了非单调结果，称为异常低剂量（ALD）现象。即电容在低伽马射线剂量时减小，然后在高剂量时异常恢复到初始值。 MLCC的几乎所有物理特性都发现了类似的情况。深入的表征有助于确认剂量依赖性的一致晶格和电子结构变化最有可能导致这种异常现象。具体来说，伽马辐照会引起带电缺陷，从而导致晶格畸变，从而减少低场反转的磁畴数量，最终导致电容下降。这项工作为BaTiO基（BTO）电介质和基于BTO的商用MLCC的伽马辐照效应提供了新的认知。