The Co_{1 − (x + y)}Mg_xNi_yCr₂O₄(where, x = y = 0.00, 0.05) nanoparticles were synthesized by the solution combustion technique using a mixture of carbamide and glucose as fuel. The refined XRD study confirmed that samples are single-phased with spinel cubic structure having space group Fd3m. The difference in ionic radius of Co²⁺ ions and Mg²⁺, Ni²⁺ ions resulted in the reduction in lattice parameters. The stretching vibration modes are found at tetrahedral and octahedral site by using FTIR spectra. Force constant value also estimated from FTIR spectra. The magnetic transition was studied by using temperature-dependent magnetization. The magnetic transitions such as ferrimagnetism transition were observed at Curie temperature (T_C = 98 K, 91 K for x = y = 0.00, 0.05, respectively), and spiral spin transition was observed at spiral temperature (T_S = 26 K, 17 K for x = y = 0.00, 0.05, respectively). Both samples show higher magnetization below spiral transition temperature (T_S).

中文翻译：

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5 mol％Mg-Ni对溶液燃烧技术制备的铬酸钴微晶结构和磁性的影响

的钴_{1 - （X  +  Ý）}的Mg _X的Ni _ý的Cr ₂ ö ₄（其中，  X  =  ÿ  = 0.00，0.05）纳米颗粒通过使用尿素和葡萄糖作为燃料的混合物的溶液燃烧技术合成。完善的XRD研究证实，样品是具有空间群Fd3m的尖晶石立方结构的单相。Co ²⁺离子与Mg 2 ⁺，Ni ^2+的离子半径之差离子导致晶格参数降低。利用FTIR光谱在四面体和八面体部位发现了拉伸振动模式。力常数值也可从FTIR光谱估算得出。通过使用随温度变化的磁化强度研究了磁跃迁。在居里温度下观察到诸如亚铁磁性转变的磁转变（对于x  =  y  = 0.00、0.05分别为T _C  = 98  K，91  K），在螺旋温度下观察到螺旋自旋转变（T _S  = 26  K，17  x  =  y的K 分别为0.00、0.05）。两种样品中显示低于螺旋转变温度（T更高磁化_小号）。