The nature and evolution of the Fe environment in Zr-Nb and Zr-Nb-Sn-Fe systems is essential to alloy performance during corrosion, hardening and irradiation-induced growth. Unfortunately, there is ambiguity in the literature regarding the characterisation of secondary phases in these systems. The presence, or not, of Fe in β-Nb phase has been a source of disagreement. In ternary ZrNbFe intermetallics, identical compositions have been designated as Zr(Nb,Fe)₂ or (Zr,Nb)₃Fe. We show that while Zr(Nb,Fe)₂ is commonly reported, it is not always justified. The cubic phase (Zr,Nb)₂Fe is easily identified, but its composition is more variable after low temperature heat treatments. We demonstrate the need for correlative approaches in the assessment of phase composition, crystallography and local Fe environment under different heat treatment regimes. Irradiation effects allow us to draw clues regarding phase designation, but there is diverse behaviour under irradiation due to initial phase composition, irradiation dose rate and temperature.

Zr-Nb和Zr-Nb-Sn-Fe系统中铁环境的性质和演变对腐蚀，硬化和辐照诱导生长期间的合金性能至关重要。不幸的是，文献中关于这些系统中次级相的表征存在歧义。β-Nb相中铁的存在与否一直是分歧的根源。在三元ZrNbFe金属间化合物中，相同的组成已指定为Zr（Nb，Fe）₂或（Zr，Nb）₃ Fe。我们显示，虽然Zr（Nb，Fe）₂通常被报道，但并不总是合理的。立方相（Zr，Nb）₂铁很容易识别，但经过低温热处理后，其成分变化更大。我们证明了在不同热处理制度下，在相组成，晶体学和局部铁环境的评估中需要相关方法。辐照效应使我们可以得出有关相名称的线索，但是由于初始相的组成，辐照剂量率和温度，辐照下的行为多种多样。