Author Topic: Investigation of X-ray Plasmon Satellites in Rare Earth Compounds  (Read 2805 times)

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Author : Ajay Vikram Singh, Dr. Sameer Sinha
International Journal of Scientific & Engineering Research, IJSER - Volume 2, Issue 4, April-2011
ISSN 2229-5518
Download Full Paper - http://www.ijser.org/onlineResearchPaperViewer.aspx?Investigation_of_X-ray_Plasmon_Satellites_in_Rare_Earth_Compounds.pdf

Abstract- We have Investigate and study to X-ray Plasmon Satellites in Rare earth compounds ( La2CuO4 , Nd2CuO4 , Gd2CuO4   ,  PrNiSb2 , NdNiSb2 , Pr(OH)3 ,  Nd(OH)3 , Sm(OH)3  )

Keywords- Surface Plasmon Satellites, Relative Intensity & Energy Separation.

IN the characteristic X-ray Spectra, Diagram as well as non Diagram lines are present. Those lines which fit in the conventional energy level diagram are called Diagram lines. & those lines which do not fit in the conventional energy level diagram are called non diagram lines. It is also known as “Satellites or Second order lines”. Satellites are generally of weak intensity lines & are found close to more intense parent line. The satellites which are observed on higher energy side are called high energy satellites (HES) whereas those are observed on lower energy side are called lower energy satellites (LES). First Siegbahn & Stenstroem observed these satellites in the K-Spectra of element from Cr (24) to Ge (32) while coster theraeus & Richtmyer in the L-Spectra of element from Cu (29) to Sb (51) & Hajlmar, Hindberg & Hirsch in the M-Spectra of elements from Yb (70) to U (92). Several theories were proposed from time to time to explain the origin of these satellites. Out of these theories the plasmon theory is found to be the most suitable theory especially for those satellites.

Plasmon theory was first proposed by Bohm & pines which are extended by Housten, Ferrel, Noziers & Pines. According to this theory the low energy plasmon satellites are emitted when valence electron excites a plasmon during the annihilation of core hole conversely if Plasmon pre exists, its energy add up to the energy of diagram line.

The radiation less reorganization of electronic shell of an atom is known as Auger effect. Auger satellites have also been observed by Korbar and Mehlhorn [1] Haynes et at. [2] Edward and Rudd [3]. Theoretical explanation for K series Auger spectrum was given by Burhop and Asaad [4] using intermediate coupling. Later on more refined theory, using  relativistic and configuration interaction has been used by Listengarter [5] and Asaad [6]
In Auger primary spectra, one can also observe secondary electron peaks close to the primary peaks are produced by incident electrons which have undergone well energy losses. The most common source of such energy loss in the excitation of collective plasma oscillations of the electrons in the solid. This gives rise to a series of plasma peaks of decreasing magnitude spaced by energy ħp where p is the frequency of plasma oscillation.  ( Download Full Paper to View Equations )
Auger peaks are also broadened by small energy losses suffered by the escaping electrons. This gives rise to a satellite on the low energy of the Auger peak. Energy loss peaks have well defined energy with to primary energy.
The involvement of Plasmon oscillation in the X-ray emission or absorption spectra of solids has been widely studied during the last few decades and has been recognized that the electron –electron interaction has played an important role.

This Paper is devoted to Investigate and study to X-ray Plasmon Satellites in Rare earth compounds     
 ( La2CuO4 , Nd2CuO4 , Gd2CuO4   ,  PrNiSb2 , NdNiSb2 , Pr(OH)3 ,  Nd(OH)3 , Sm(OH)3  )

According to Plasmon theory ,  if the valence electron , before filling the core vacancy , also excites a Plasmon ,then the energy ħωp needed for the excitation of Plasmon oscillation is taken from the transiting valence electron so that the emitted radiation will be derived off an energy ħωp and a low energy satellites will emitted whose sepration from the main X-ray line will correspond to ħωp . On the other hand if the Plasmon pre exists , during the X-ray emission process , then , on its decay it can give its energy to the transiting valence electron before it annihilates the core vacancy . Thus the energy of emitted X-ray photon will be higher than the main emission line and by an amount ħωp giving rise to high energy satellite .

MATHEMATICAL CALCULATION –
In order to confirm the involvement of Plasmon in the emission of X-ray satellites the relative intensity of single Plasmon satellites must be calculated . In this process first we deal with mathematical details of canonical transformation carried out over the model Hamiltonian of the system .


Read More: http://www.ijser.org/onlineResearchPaperViewer.aspx?Investigation_of_X-ray_Plasmon_Satellites_in_Rare_Earth_Compounds.pdf