Analysis of Cerium-Substituted Yttrium Iron Garnets Using Inductively Coupled Plasma Atomic Emission Spectrometry with Preliminary Decomposition in a Microwave System

Abstract

A method for analyzing iron garnets of the composition Y_3–xCe_xFe_5–yGa_yO₁₂, where x = 0.4–0.5 and y = 2.4–2.6, using inductively coupled plasma atomic emission spectroscopy (ICP-AES) with preliminary decomposition of the sample in microwave system is described. During the investigation, conditions for microwave decomposition of samples are studied and selected—the composition of acid mixtures (HCl/HNO₃) and modes of microwave heating (holding time and temperature) providing complete dissolution of the samples. Conditions for ICP-AES analysis of cerium-doped yttrium iron garnets and the effect of matrix components (Y, Ce, Fe, and Ga) on the determination of impurity elements are studied. The operating parameters of the spectrometer (high-frequency generator power and argon spray flow rate) making it possible to reduce the matrix effect when determining Na, Mg, Al, Si, P, K, Ca, Sc, Cr, Mn, Co, Ni, Cu, Zn, Se, Cd, Sn, Te, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Pb impurities in yttrium iron garnets using ICP-AES are selected in order to minimize the matrix effect. ICP-AES studies are carried out in axial and radial modes for impurity elements and in radial modes for matrix elements. The limits of quantification (LOQs) of most analytes are in the range from n × 10^–5 to n × 10^–4 wt %. The accuracy is confirmed by the “spike–recovery” method, as well as by the analysis of samples with certified element contents. The standard deviation is in the range from 1 to 5% depending on the selected plasma viewing mode and the elements being detected. The developed method makes it possible to determine macro- and microcomponents in yttrium iron garnets in a wide range of concentrations with a high accuracy.