Magnetic susceptibility of the rare earth element impurities in the IV–VI semiconductors and Curie–Weiss law

A review of high magnetic moment thin films for microscale and nanotechnology applications

“…But these results neither undoubtedly confirmed a "colossal" moment nor seemed the reproduction of the FM systems a fully developed method 374 and impurities as well as the formation of RE oxides were found to be another complication. 375 In summary, it can be said that, even assuming a "colossal" moment for Gd atoms (and large spontaneous magnetic moments of other heavy RE metals), the overall saturation magnetisation is far too small for high-moment applications. Theoretical understanding so far contradicts potential use in future devices, as the additional magnetic moment requires a large surrounding GaN matrix.…”

Segregation of the Eu impurity as function of its concentration in the melt for growing of the lead telluride doped crystals by the Bridgman method

“…[15]). Secondly, during growth of the PbTe crystals from the melt doped with REE, the "REE impurity -Oxygen" complexes are formed with high probability at the beginning of doped crystal and absent at its end [11].…”

“…As shown above the surface layers of the ingot grown from melt with low initial impurity concentration practically does not contain the single Eu centers whereas only the single Eu 2+ centers are identified in the end part of PbTe:Eu(Gd) ingots grown from the melt with high initial impurity concentration [9,11]. The former means that in the surface layers where the doping impurity is pushed out during growth of doped crystals from the melt with the low initial impurity concentration there always are suitable conditions for complex formation.…”

“…In practice it is very difficult to grow the doped crystals containing only the single impurity centers. Usually they contain also the pairs and triplets of the impurities as well as more complicated formations [7][8][9], and the complexes of the REE with Oxygen [10,11]. Moreover the rare earth impurities are strongly non-uniformly distributed along the doped crystals during their growth from melt [12][13][14].…”

Complex formation and background impurity of Oxygen in the PbTe:Eu doped crystals grown from melt by the Bridgman method

“…Vast database has been accumulated on the behavior of the impurities of different REE, first of all Eu [1][2][3][4][5][6][7], Gd [8][9][10][11][12][13][14][15], Ce, Pr, Nd [16][17][18], and Yb [18][19][20], and their effect on the properties of IV-VI semiconductors. Since the REE impurities have uncompensated spin moments of the inner 4f electrons, the magnetization and measurements of M S are widely used in the studies of their behavior.…”