Analysis of S-d Exchange Interactions in Dilute Cu-mn Alloys

abbreviation of S-d Exchange Interactions in Dilute Cu-mn AlloysPhenomenological summary of the s-d exchange fundamental interactions in dilute Cu-Mn alloys at helium temperaturesAL-Jalali, M. A.AbstractThe S-d exchange interactions in dilute Cu-Mn alloys was canvas on assiduousness ( C ) varying in the midst of 10.5 and 2081.8 ppm of Mn in Cu within the ( 0.03K 4.2K ) temperature range. apply electrical electrical resistance data on those alloys, the s-d exchange integral ( Jsd ), which is negative, has waitd to show a pardon dependence on (Ln C). This dependence, confirming thus the dominance of Kondo effect be pocket-sized 1000 ppm impurity assimilation, alone above this concentration, we expected an interference between Kondo effect and spin ice regime, which mean that spin trash regime has to prevail more than Kondo effect. Keywords s-d interaction electrical resistivity Jsd Kondo effect spin deoxyephedrine. PACS 75 50, 7510, 75 40, 75 30.IntroductionThe main objec tive of this paper is to study the huge effects on the coupling between the dilute magnetic impurities (Mn), which generates rise to the formation of local magnetic moments, and the conduction electrons from the military noble metal (Cu).Electrical resistivity is a great source of information, especially to get the value of the s-d exchange integral Jsd .For a very dilute alloys (concentration below 100 ppm of Mn), the low-temperature resistivity is dominated by an anomalous Kondo scattering of the conduction electron spin at the local magnetic moments. A typical logarithmic divergence of the resistivity volition begin above the Kondos temperature( TK ) until the minimum in the resistivity of Cu-Mn Kondo alloys, where higher temperatures is prevailed, and when the magnetic impurity concentrationIncreasing until ( 1 at. %), the interaction between the local magnetic moments and conduction electrons ,which is governed by the Ruderman-Kittel-Kasuya-Yosida (RKKY) 1,2,3 interaction will form a spin-glass phase 4.The method, I have used, to calculate Jsd was the analysis of crude observational data and by simi-emperical simple calculating, I found that the Jsd decreases logarithmically with concentration and gives a very important information about competition between Kondo effect and spin glass regime5, which inquire a deeper study in the future.Theoretical backgroundThe introduction of few ppm of 3d or 4f magnetic impurity in a non-magnetic matrix leads to an s d exchange interaction between the spins of the conduction electrons Se and the Localized magnetic moment Sd of the transition element, which can be described by a HamiltonianWhere (Jsd) is the exchange coupling parameter, and is any ordinary scattering from the ion carrying the local moment. With a negative Jsd, the interaction leads to an increase of localized spin trouble resistivity with decreasing temperature.The competition between the spin disorder scattering and the phonon exhibits the mini mum in the resistivity of this regime 6, 7, 8, 9. Phenomenologically the above competition is mainly manifested at low temperatures in the formWhere the spin scattering resistivity, and, ( EF =the Fermi energy),(Z=number of conduction electrons per atom).In this work, I drive to show the behaviour of Jsd in some Cu Mn alloys, despite the fact that there is the mint of information has been put forward on these alloys during and after the 1980s, the electrical resistivity one of many sources to impart a powerful means to trace the s d exchange interaction dominating these alloys.Analysis of dataMatula and others reported crude data 10, 11, 12 on electrical resistivity and methods of manufacturing of alloys, especially in complaisance of purity, constituting the major experimental background in this work. They come from direct measurements already carried on Cu Mn alloys (and many others noble transition metals alloys) with concentrations ranging from 10.5 ppm to 2081.3 ppm of M n in Cu within the ( 0.03 4.2K ) range 11, 12,13 .Figure (1) scales versus Ln (T/c) give us by suit fitting an expression like a logarithm of power serial publication solutionThe first two terms (first- order approximation) show a bold line at figure (1), where pure magnetic resistivity could be defined from that lines as a function of ( LnT), and by using a fittings programming we can find from the ones of the bold lines a coition as following (figure(2)) -This matches with Hamanns expression 13, 14, 15, and 16 Tk =Kondo temperatureFigure (2) expresses exactly what a compatible between experimental relation (4) and theoretical Hamanns expression (5) there are.Definitely, allowing the inclusion of potential scattering effect with atomic number 53 impurity kondo effect, and sharp determination of kondo temperature Tk = 36 mK. Calculated values of Jsd reveal a variation(C is Mns concentration in ppm units), as it has shown in figure (3).Expression ( 6 ) was calculated according t o a breadth of internal field distribution 12,16 at Tmax ( characterize the maximum value of the resistivity at figure(1)(7)Results and passwordAs it is shown in figure ( 3 ), above 850 ppm, our calculation to Jsd leads, just as other whole kit do 12,17 , 18 , 19, 20 to believe that magnetic transformation takes place from antiferromagnetic to ferromagnetic allege and between 860 ppm and 2000 ppm may be a spin glass regime starts to prevail.When we come back to Kondos temperature at Hamanns expression (5), it is most appropriately to denote that the Kondos temperature given as 21Where, initially, TF =8.12 104 k, and n (EF) =0.294 ev-1.It seems that Tk is not constant as we noted above, and is not consistent with 22, And has clear dependence on Jsd . Of course, we need more studying to pursue this point.Finally, as a instead of conclusion put (Result), and from figure (3), we can classify a Kondos regime in respect of concentration as followingpure kondo regime vanishes at con centration 63 ppm of magnetic impurity (Mn) .Mixed regime ( kondo + SG ) from 63 ppm to 860 ppm.Ideal spin glass from 860 ppm to about 1%.ConclusionWhen we increase the concentration of magnetic impurity, The s-d exchange interactions will move to RKKY interactions, where Jsd will represent a phenomenological order parameter, which reflects a shift of interactions between conduction electrons and localized magnetic moments and discovers the in the buff magnetic transformation from a regime to be other.1