Ž . Spectrochimica Acta Part B 56 2001 13671374 Chemical effects on K K  X-ray intensity ratios of Mo, Ag, Cd, Ba, La, Ce compounds and total mass attenuation coefficients of Fe and Cu ¨ a,  a b a c O. Sogut , S. Seven , E. Baydas ¸ , E. Buyukkasap , A. Kuc ¸ ukonder ¨ˇ¨ ¨¨ ¨¨¨ a Ataturk Uni  ersity, Education Faculty, Department of Physics Education, 25240 Erzurum, Turkey ¨ b Ataturk Uni  ersity, Faculty of Arts and Sciences, Department of Physics, Erzurum, Turkey ¨ c ˙ Sutc ¸ u Imam Uni  ersity, Faculty of Arts and Sciences, Department of Physics, Kahramanmaras ¸ , Turkey ¨¨ Received 22 January 2001; accepted 17 May 2001 Abstract The KK  intensity ratios for pure Mo, Ag, Cd, Ba, La and Ce elements and for some of their compounds were investigated. The vacancies in the K shell were created by 59.5-keV -rays from a heavily filtered 241 Am radioactive Ž . source. K X-rays were measured using a Si Li detector with a resolution of 155 eV at 5.9 keV. We observed chemical effects on KK  intensity ratios of Mo, Ag, Cd, Ba, La and Ce compounds. Detailed interpretation of data obtained from X-ray transmission measurements usually depends on the assumption that the contribution of each element is additive. This assumption yields the mixture rule for X-ray attenuation coefficients which is valid if molecular and chemical effects are negligible. We measured the total mass attenuation coefficients of Fe and Cu in various compounds. Self-absorption corrections were carried out on data for ligands in the different compounds. Our values were compared with the theoretical values for pure elements.  2001 Elsevier Science B.V. All rights reserved. Keywords: KK  intensity ratios; Chemical effect; Attenuation coefficients 1. Introduction It is well known that X-ray spectra depend on  the chemical states of atoms 1 and extensive  Corresponding author. Ž . E-mail address: omer sogut@yahoo.com O. Sogut . ¨ˇ¨  experimental studies for the chemical effects on the KK  X-ray intensity ratios of 3d transi-   tions elements have been reported 2  13 . The physical state and chemical combination of ele- ments affect the characteristic X-rays. The chemi- cal effects correspond to the fact that valence electrons participating in the formation of a chemical bond are removed from the atom. The 0584-854701$ - see front matter  2001 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 5 8 4 - 8 5 4 7 01 00238-5