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The chemical states of powder surfaces depend on the manufacturing processes of the powders. The surface chemistry of three different commercial AIN powders, which are processed by carbothermal nitridation of Al2O3, chemical vapor deposition (CVD), and direct nitridation of aluminum, were evaluated by using Auger electron spectroscopy (AES). In order to obtain reference AES spectra of aluminum compounds, α‐, γ‐, θ‐Al2O3, γ‐AIOOH, γ‐AION, and sintered AIN were also examined. Line shapes of aluminum LVV; Al(LVV), nitrogen KLL; N(KLL) and oxygen KLL; O(KLL) are discussed for the AIN powders and all the other aluminum compounds. The differential Auger electron spectra, i.e., E dn/AE were obtained directly, where n is the number of Auger electrons, and E is the kinetic energy of the electron. Their integrated spectra, i.e., n(E) are also employed for analysis. The results confirm the conclusions of our previous temperature‐programmed desorption work. The AES line shape analysis implies the presence of an oxide‐like θ‐Al2O3 containing AION phase on the carbothermal nitride AIN powder surfaces. The surfaces of CVD and direct‐nitrided AIN powders are covered by an oxide–like γ‐Al2O3 with an oxygen diffusion layer and does not have AION phase.

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