Microwave combustion technique (MCT) was used to synthesize of spinel Ni_1-xSr_xFe₂O₄ (x = 0.0, 0.1, 0.3 and 0.5) nanoparticles (NPs) by employing the fuel L-arginine. The physical characteristics of the as-prepared NPs were obtained by following methods, viz., powder X-ray diffraction (XRD), high-resolution scanning electron microscope (HR-SEM), energy-dispersive X-ray (EDX), UV-visible diffuse reflectance spectra (UV-Vis DRS), Fourier-transform infrared spectra (FT-IR), and vibrating sample magnetometer (VSM) techniques. The diffraction studies revealed that the average crystallite size exists in the band of 14.25 to 27.52 nm. The HR-SEM pictures revealed the agglomerated and spherical morphology of spinel Ni_1-xSr_xFe₂O₄ (x = 0 to 0.5) nanoparticles. Elemental analysis ensured the existence of Ni, Sr, O, and Fe ions. The energy band gap of the NPs was observed to exist in the range of 2.95 to 3.39 eV upon varying the concentration of Sr²⁺ dopant. The broad peaks at 437 cm⁻¹ and 582 cm⁻¹ correspond to octahedral (B-) metal stretching (Ni-O) and tetrahedral (A-) metal stretching (Fe-O) of nickel ferrite respectively. Magnetic results revealed that the prepared NPs are ferromagnetic in nature. The antibacterial activity (ABA) of gram-positive Staphylococcus aureus and Bacillus subtilis and gram-negative Escherichia coli and Klebsiella pneumonia has been investigated using pure and Sr²⁺-substituted NiFe₂O₄ NPs. It was found that the improved activity is intensified with smooth Sr²⁺ doping as it causes a decrease in the grain size.

微波燃烧技术（MCT）用于合成尖晶石Ni _{1- x} Sr _x Fe ₂ O ₄（x = 0.0、0.1、0.3和0.5）纳米粒子（NPs）通过使用燃料L-精氨酸。制备的NP的物理特性是通过以下方法获得的，即粉末X射线衍射（XRD），高分辨率扫描电子显微镜（HR-SEM），能量色散X射线（EDX），UV可见漫反射光谱（UV-Vis DRS），傅立叶变换红外光谱（FT-IR）和振动样品磁力计（VSM）技术。衍射研究表明，平均晶粒尺寸存在于14.25至27.52 nm的谱带中。HR-SEM照片显示了尖晶石Ni _{1- x} Sr _x Fe ₂ O ₄（x的聚集和球形形态 = 0至0.5）纳米粒子。元素分析确保了Ni，Sr，O和Fe离子的存在。通过改变Sr ²⁺掺杂剂的浓度，可以观察到NP的能带隙在2.95至3.39 eV的范围内。437 cm ^-1和582 cm ^-1处的宽峰分别对应于镍铁氧体的八面体（B-）金属拉伸（Ni-O）和四面体（A-）金属拉伸（Fe-O）。磁性结果表明，所制备的NP在本质上是铁磁性的。革兰氏阳性金黄色葡萄球菌和枯草芽孢杆菌以及革兰氏阴性大肠杆菌和克雷伯菌肺炎的抗菌活性（ABA）已经使用纯的和Sr ²⁺取代的NiFe ₂ O ₄ NPs进行了研究。发现通过光滑的Sr ²⁺掺杂增强了改进的活性，因为它引起晶粒尺寸的减小。