RAMAN CHARACTERIZATION OF CuCr2-xSnxS4 SPINELS

Abstract

Polycrystalline thiospinels CuCr 2-x Sn x S 4 (x = 0.4, 0.8, 1.0 and 1.4) were synthesized via conventional solid-state reaction. The samples were characterized by powder X-ray diffraction (XRD), energy-dispersive X-ray analysis (SEM-EDS) and Raman spectroscopy. All the samples were indexed in the space group. The Raman spectra confirmed the structure of normal spinel type with five characteristic signals for the active modes in Raman. Magnetic measurements, performed for the phases with x = 0.8 and 1.0, showed irreversible antiferromagnetism with dominant ferromagnetism and spin glass behavior.

Tailoring the thermoelectric and structural properties of Cu–Sn based thiospinel compounds [CuM1+xSn1−xS4 (M = Ti, V, Cr, Co)]

“…35,73 The effective magnetic moment μeff = 3.97 μB per Cr atom obtained from the fitting of the high-temperature region is close to the theoretical value μeff = 3.87 μB for octahedral coordination of Cr 3+ with S = 3/2 and an electronic configuration of t2g 3 (d 3 configuration), which is consistent with a previous report. 39 The temperature dependence of the magnetic susceptibility of CuCo0.5Sn1.5S4 is shown in Figure 4b. The material itself appears to be close to be paramagnetic.…”

“…In the same way as that of Cu-Ti-Sn thiospinel, the charge balance for x = 0 can be described Cu + Cr 3+ Sn 4+ (S 2-)4 and a global charge balance of Cu + Cr 3+ (Cr 4+ )x(Sn 4+ )1-x(S 2-)4. 39,40 for composition x > 0. The octahedral occupancy by Cr 3+ is responsible for the p-type conduction.…”

“…However, some reports have confirmed the formation of Cr 4+ for the x > 0 composition, according to the magnetic moment expected for a high spin state of Cr, leading to a global charge balance of Cu + Cr 3+ (Cr 4+ )x(Sn 4+ )1x(S 2-)4. 39,40 To the best of our knowledge, the thermoeelctric properties have never been investigated on dense samples at a higher temperature range for such Cu-Sn based thiospinel compounds before. This propels the motivation for this work, where a large variety of compositions of CuM1+xSn1-xS4 (M = Ti, V, Cr, Co) are explored regarding their thermeoelectrtic properties for the first time.…”

(Cu)tet(Cr2–xSnx)octS4–ySey Spinels: Crystal Structure, Density Functional Theory Calculations, and Magnetic Behavior

“…The spectra, which are characterized by the presence of five signals at approximately 130, 190, 299, 337, and 382 cm −1 , compare very well to the spectra of ACr 2 X 4 spinels (A = Cd, Hg, Cu, or Zn and X = S or Se) 42−48 and CuCr 2−x Sn x S 4 spinels, with tin substitution in octahedral positions. 49 The signals undergo a shift at higher vibrational frequencies with respect to the end-members, as shown in Table 2. Comparative spectra are shown in Figure S5.…”

Effects of Tin and Sulfur Chemical Substitution on the Structural and Electrical Properties of CuCr2Se4 Selenospinel

“…This has been the focus of many studies because of its potential for use in new data storage devices with reduced energy consumption [2,3]. Therefore, solid solutions of seleno-and thiospinels have been well studied because of their extraordinary electrical and magnetic properties, which can differ significantly by substitution [4][5][6][7][8][9][10][11]. For example, replacing metal ions in the octahedral or tetrahedral position with diamagnetic ions can alter the magnetic properties of CuCr2S4 and CuCr2Se4.…”