The Zn1−xPbxCr2Se4—Single Crystals Obtained by Chemical Vapour Transport—Structure and Magnetic, Electrical, and Thermal Properties

Abstract

Monocrystalline chalcogenide spinels ZnCr2Se4 are antiferromagnetic and semiconductor materials. They can be used to dope or alloy with related semiconducting spinels. Therefore, their Pb-doped display is expected to have unique properties and new potential applications. This paper presents the results of dc and ac magnetic measurements, including the critical fields visible on the magnetisation isotherms, electrical conductivity, and specific heat of the ZnCr2S4:Pb single crystals. These studies showed that substituting the diamagnetic Pb ion with a large ion radius for the Zn one leads to strong short-range ferromagnetic interactions in the entire temperature range and spin fluctuations in the paramagnetic region at Hdc = 50 kOe.

Synthesis, Structure, and Physicochemical Characteristics of Zn1−xRexCr2Se4 Single Crystals

“…The thermal energy kT opposes this phenomenon. Similar peaks were observed in the ZnCr 2 Se 4 crystals doped with Al [ 56 ], Ce, Ga, In [ 57 ], and Pb [ 18 ].…”

“…The thermal energy kT opposes this phenomenon. Similar peaks were observed in the ZnCr 2 Se 4 crystals doped with Al [56], Ce, Ga, In [57], and Pb [18]. Additionally, the Curie constant C and the effective moment µeff are slightly higher than the chromium ion value per molecule.…”

“…It is confirmed that the rhenium ions influence the magnetic moment. For H dc = 50 kOe, the J 1 superexchange integral for the first coordination sphere changes the sign from negative to positive, while the J 2 integral remains positive (not shown here), as in Zn 1−x Pb x Cr 2 Se 4 [ 18 ].…”

“…The structural parameters were calculated based on the procedure depicted in Refs. [ 18 , 31 ]. The results showed that the Re ions share the tetrahedral positions with Zn-cations in every fifth crystal.…”

“…Numerous experimental and theoretical studies have been devoted to ZnCr 2 Se 4 doped with various elements. The matrix was doped with p -elements (Al, Ga, In, Sn, and Pb [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]), d -elements (Cu, Mn, Ni, and Ta [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]), and f -elements (Dy, Gd, Ho, and Nd [ 27 , 28 , 29 , 30 , 31 ]).…”