Cr-Doped TiSe₂ – A Layered Dichalcogenide Spin Glass

Abstract

We report the magnetic characterization of the Cr-doped layered dichalcogenide TiSe 2 . The temperature dependent magnetic susceptibilities are typical of those seen in geometrically frustrated insulating antiferromagnets. The Cr moment is close to the spin-only value, and the Curie Weiss thetas (θ CW ) are between -90 and -230 K.Freezing of the spin system, which is glassy, characterized by peaks in the ac and dc susceptibility and specific heat, does not occur until below T/θ CW = 0.05. The CDW transition seen in the resistivity for pure TiSe 2 is still present for 3% Cr substitution but is absent by 10 % substitution, above which the materials are metallic and p-type. Structural refinements, magnetic characterization and chemical considerationsindicate that the materials are of the type Ti 1-x Cr x Se 2-x/2 for 0 ≤ x ≤ 0.6.

Intrinsic insulating ground state in transition metal dichalcogenide TiSe2

“…Both Se flux and pressure growths have smaller lattice parameters, perhaps attributable to the absence of larger iodine atoms that might replace Se, or the result of slight lattice compression due to the higher pressure during nucleation. This shift is much smaller than that brought about by small amounts of chemical dopants or intercalants 10,11,16 . Among pressure-grown samples, there is again no trend in lattice size with the amount of Ar pressure applied.…”

“…Both the application of high pressure and the intercalation or substitution of new atoms to TiSe 2 have been used to change the character of the CDW, generally suppressing it and in some cases leading to superconductivity or magnetic ordering [9][10][11][12][13][14][15][16] . In this paper, we present a way of stabilizing new properties in TiSe 2 at ambient pressure without the use of additional atoms.…”

Interplay between Charge-Density-Wave, Superconductivity, and Ferromagnetism in CuIr2–xCrxTe4 Chalcogenides

“…This phenomenon is also observed in Ti1-xCrxSe4, in which the effective moment is ~ 4 μB, and is basically not affected by the change of Cr content. 53 In the meantime, the magnetic susceptibility of CuIr2-xCrxTe4 (0 < x ≤ 0.2) roughly follows Curie-Weiss law under the normal state without any magnetic phase transition. susceptibility in an applied magnetic field 1 T can be also fitted using the modified Curie-Weiss law ꭓ = ꭓ0 + C/(T-θ).…”

“…Ferromagnetism is frequently observed in Cr intermetallic compounds and Cr-doped compounds, such as for the two-dimensional (2D) ferromagnets Cr2Ge2Te6 [54][55][56] and Cr-doped layered dichalcogenide TiSe2. 53 The M-H curves are essentially linear at T > Tc, indicating a simple paramagnetic state. The saturated moment at 2 K for CuIr1.7Cr0.3Te4, CuIr1.65Cr0.35Te4, and CuIr1.6Cr0.4Te4 are 0.60, 0.87, and 0.67 μB Cr-ion -1 , respectively.…”

Review of nanoscale layered transition metal chalcogenide superconductors

“…The 4Hb and 6R forms are mixed octahedral−trigonal polymorphs. As with the 2Ha, the 2Hb and 3R consist only of trigonal prisms [49][50][51][52][53].…”