Dadwal Kajal, Fábián Margit, Tolnai Istvan, Sharma Suruchi, Kaur Rajinder, Gracheva Maria, Kovács Krisztina, Klencsár Zoltán, Khanna Atul
Sensors and Glass Physics Laboratory, Department of Physics, Guru Nanak Dev University Amritsar 143005 Punjab India
HUN-REN Centre for Energy Research Konkoly-Thege Miklós út 29-33 1121 Budapest Hungary.
RSC Adv. 2025 Feb 17;15(7):5286-5304. doi: 10.1039/d5ra00295h. eCollection 2025 Feb 13.
FeO-(100 - )PO glasses were synthesized by melt quenching and structure-property correlation studies were carried. Glasses containing 25 to 40 mol% FeO were prepared while the sample with 50 mol% FeO formed a crystalline sample containing Fe Fe [PO] and Fe [PO] phases on melt-quenching. Glass density increases from 2.98 to 3.20 g cm, ionic packing fraction is in the range of 0.63-0.65 and the glass transition temperature decreases from 500 °C to 493 °C on increasing FeO concentration from 25 to 40 mol%. Pair distribution function analysis and Reverse Monte Carlo simulations of neutron diffraction datasets were used to calculate the atomic pair distributions, interatomic distances and co-ordination environments. The P-O co-ordination is essentially tetrahedral and is in the range: 3.9-3.7 (±0.1), the Fe-O co-ordination number decreases steadily from 4.8 to 4.2 (±0.1) with an increase in FeO concentration in the phosphate network, while O-O co-ordination is in the range: 6.6-6.3(±0.1), the decrease in these co-ordination numbers are due to an increase in oxygen deficiency in the glass network with an increase in FeO mol%. Fe-O and P-O pair distributions are asymmetrical indicating short-range disorder due to the existence of a wide range of bond-lengths with maxima at 1.79 Å and in the range: 1.45-1.51 Å respectively. Mössbauer studies carried out at room temperature and 80 K found that Fe exists in 2+ and 3+ valence states, and the glass and crystalline samples contained Fe at least at three different sites. Raman studies found that the and pyrophosphate structural units are dominant species up to 35 mol% FeO concentration, while the orthophosphate units are in majority at 40 mol% of FeO. The crystalline sample is a two phase material and contained both orthophosphate and pyrophosphate units with the former being the dominant species. Leaching studies on two iron phosphate glasses carried out in purified water at 90 °C found that dissolution of glasses decreases and the chemical durability increases drastically with an increase in FeO mol%.
通过熔融淬火法合成了FeO-(100 - )PO玻璃，并进行了结构-性能相关性研究。制备了FeO含量为25至40摩尔%的玻璃，而FeO含量为50摩尔%的样品在熔融淬火时形成了含有FeFe[PO]和Fe[PO]相的晶体样品。随着FeO浓度从25摩尔%增加到40摩尔%，玻璃密度从2.98克/立方厘米增加到3.20克/立方厘米，离子堆积分数在0.63 - 0.65范围内，玻璃转变温度从500℃降至493℃。利用对分布函数分析和中子衍射数据集的反向蒙特卡罗模拟来计算原子对分布、原子间距离和配位环境。P-O配位基本上是四面体配位，范围为：3.9 - 3.7(±0.1)，随着磷酸盐网络中FeO浓度的增加，Fe-O配位数从4.8稳定下降至4.2(±0.1)，而O-O配位范围为：6.6 - 6.3(±0.1)，这些配位数的减少是由于随着FeO摩尔%的增加，玻璃网络中氧缺陷增加。Fe-O和P-O对分布不对称，表明由于存在范围广泛的键长，分别在1.79 Å和1.45 - 1.51 Å范围内出现最大值，从而导致短程无序。在室温及80 K下进行的穆斯堡尔研究发现，Fe以2 +和3 +价态存在，玻璃和晶体样品中至少在三个不同位置含有Fe。拉曼研究发现，在FeO浓度达到35摩尔%之前，和焦磷酸盐结构单元是主要物种，而在FeO含量为40摩尔%时，正磷酸盐单元占多数。该晶体样品是一种两相材料，同时包含正磷酸盐和焦磷酸盐单元，前者是主要物种。在90℃的纯水中对两种磷酸铁玻璃进行的浸出研究发现，随着FeO摩尔%的增加，玻璃的溶解减少，化学耐久性急剧增加。
