The effect of Ti substitution for Cr on transport and thermoelectric properties of CrSb2 at low temperatures

Rewritable Pressure-Driven n–p Conduction Switching in Marcasite-Type CrSb2

“…At room temperature, the narrow-gap semiconductor CrSb 2 exhibits excellent photocurrent responses. In addition to the measurements of thermoelectric power and Hall coefficient, photocurrent measurements are also useful tools for probing the type and density of carriers under HP. ,− At initial pressure, the sample shows n -type conductivity, consistent with the reported results of thermoelectric power and Hall resistance measurements. ,, At low pressures, the photocurrent responses are slightly enhanced by applying pressure. Upon increase in the pressure to 11.8 GPa, the direction of photocurrent switches, indicating that the carrier type changes from electrons to holes, that is an n – p switching, upon the structural phase transition.…”

“…3d Transition-metal dichalcogenides and dipnictides (MX 2 ) crystallizing in marcasite-, pyrite-, and arsenopyrite-type structures have been thoroughly studied for their structural relationship and bonding schemes. , These compounds have also received extensive attention due to their potential applications in thermoelectric materials. − Recently, researchers have found more new structures of these compounds through high-temperature and high-pressure synthesis. − The structures mentioned above can transform into each other under suitable conditions. Marcasite-type CrSb 2 is a narrow-gap semiconductor with a band gap of ∼0.07 eV and exhibits an antiferromagnetic behavior with T N ≈ 273 K and a magnetic moment of 1.94 μ B /Cr. − Through thermoelectric power and Hall resistance measurements, it can be confirmed that CrSb 2 shows n -type conducting behavior under ambient conditions. , In addition, Takizawa et al prepared another phase of CrSb 2 with a CuAl 2 -type structure using high-temperature and high-pressure (HT-HP) synthesis . Herein, we focus on marcasite-type CrSb 2 and perform detailed in situ characterizations for the evolutions of structure and physical properties under HP.…”

Resistivity, thermopower, and thermal conductivity of nickel doped compounds Cr1−xNixSb2 at low temperatures

“…suggests that a shift in impurity or defect levels toward the edge of conduction band(s), or even a narrowing of the energy gap would occur due to lattice distortion after doping (Fig. 2), which is well consistent with previous results [39,41]. On the other hand, the donor level could be introduced into the energy gap of CrSb 2 after Ni substitution.…”

“…Additionally, the Neel temperature of CrSb 2 shifts to higher temperatures after Mn substitution, owing to the high spin 3d 3 configuration of Mn [40]. In contrast, the change of Neel temperature could be negligible after Ti substitution due to neutral particles of Ti [41]. It is well known that NiSb 2 and CrSb 2 have the same crystalline structure [30,42], furthermore, it is the low spin 3d 6 configuration of Ni in NiSb 2 [32].…”

“…Moreover, CrSb 2 is a narrow-gap semiconductor with an energy gap of 0.07 eV [31,38], suggesting that CrSb 2 would be a potential thermoelectric material. Recently, we have studied the transport and thermoelectric properties of CrSb 2 after the substitution of Te, Sn, Mn, Ti for Cr, respectively [29,[39][40][41]; and the ZT of CrSb 2−x Te x , Cr 1−x Mn x Sb 2 , and Cr 1−x Ti x Sb 2 were improved by an appropriate doping, however, the thermoelectric properties of CrSb 2−x Sn x were not optimized due to the decrease in the thermoelectric power factor (PF = S 2 T/ ). Additionally, the Neel temperature of CrSb 2 shifts to higher temperatures after Mn substitution, owing to the high spin 3d 3 configuration of Mn [40].…”