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Publication

Quasi-two-dimensional heterostructures (KM1 (-) Te-x)(LaTe{s

Authors

Bao, Jin-Ke; Malliakas, Christos; Zhang, Chi; Cai, Songting; Chen, Haijie; Rettie, Alexander; Fisher, Brandon; Chung, Duck Young; Dravid, Vinayak ; Kanatzidis, Mercouri

Abstract

Layered heterostructure materials with two different functional building blocks can teach us about emergent physical properties and phenomena arising from interactions between the layers. We report intergrowth compounds KLaM1 - xTe4 (M = Mn and Zn; x approximate to 0.35) featuring two chemically distinct alternating layers [LaTe and [KM1 - xT. Their crystal structures are incommensurate, determined by single X-ray diffraction for the Mn compound and a transmission electron microscope study for the Zn compound. KLaMn1 (-) Te-x(4) crystallizes in the orthorhombic superspace group Pmnm(01/2 gamma)s00 with lattice parameters a = 4.4815(3) A, b = 21.6649(16) A, and c = 4.5220(3) A. It exhibits charge density wave order at room temperature with a modulation wave vector q = 1/2b* + 0.3478c* originating from electronic instability of Te-square nets in [LaTe layers. The Mn analog exhibits a cluster spin glass behavior with spin freezing temperature T-f approximate to 5 K attributed to disordered Mn vacancies and competing magnetic interactions in the [Mn1 - xT layers. The Zn analog also has charge density wave order at room temperature with a similar q-vector having the c* component similar to 0.346 confirmed by selected-area electron diffraction. Electron transfer from [KM1 - xT to [LaTe layers exists in KLaM1 (-) Te-x(4), leading to an enhanced electronic specific heat coefficient. The resistivities of KLaM1 - xTe4 (M = Mn and Zn) exhibit metallic behavior at high temperatures and an upturn at low temperatures, suggesting partial localization of carriers in the [LaTe layers with some degree of disorder associated with the M atom vacancies in the [M1 - xT layers.

Division

MSD

Publication Year

2021

Publication Type

Article

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