Spin reorientations in structurally metastable, disordered, and hexagonal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>Cr</mml:mi> <mml:mn>7</mml:mn> </mml:msub> <mml:msub> <mml:mi>Te</mml:mi> <mml:mn>8</mml

Vapor deposited two-dimensional <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mrow> <a:msub> <a:mi>Cr</a:mi> <a:mn>7</a:mn> </a:msub> <a:msub> <a:mi>Te</a:mi> <a:mn>8</a:mn> </a:msub> </a:mrow> </a:math> displays unusual temperature dependent Hall effect properties, including a room-temperature anomalous Hall effect, sign reversals of the Hall resistivity on cooling, and a peak in the Hall resistivity at low temperatures. The two-dimensional <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:mrow> <b:msub> <b:mi>Cr</b:mi> <b:mn>7</b:mn> </b:msub> <b:msub> <b:mi>Te</b:mi> <b:mn>8</b:mn> </b:msub> </b:mrow> </b:math> heterostructures that form the basis of these measurements are hexagonal in structure. We study the magnetic and structural properties of bulk <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"> <c:mrow> <c:msub> <c:mi>Cr</c:mi> <c:mn>7</c:mn> </c:msub> <c:msub> <c:mi>Te</c:mi> <c:mn>8</c:mn> </c:msub> </c:mrow> </c:math> synthesized by quenching from <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mrow> <d:mn>1000</d:mn> <d:msup> <d:mspace width="0.16em"/> <d:mo>∘</d:mo> </d:msup> <d:mi mathvariant="normal">C</d:mi> </d:mrow> </d:math> with the goal of relating the magnetic, structural, and electronic properties. This quenched phase is metastable, hexagonal, and displays different magnetic properties from the slow-cooled and more thermodynamically stable monoclinic phase. High-resolution x-ray diffraction of the quenched hexagonal phase finds a first-order transition to a lower symmetry monoclinic phase on above <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"> <g:mo>∼</g:mo> <g:mn>550</g:mn> </g:math> K. Magnetic susceptibility measurements of the quenched hexagonal phase reveal ferromagnetic ordering above room temperature, along with the two distinct transitions at <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"> <h:mo>∼</h:mo> <h:mn>220</h:mn> </h:math> K and <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"> <i:mo>∼</i:mo> <i:mn>70</i:mn> </i:math> K. Through neutron diffraction studies, we find the <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"> <j:mo>∼</j:mo> <j:mn>220</j:mn> </j:math> K anomaly is a spin reorientation transition of the ferromagnetically aligned magnetic moments and the <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"> <k:mrow> <k:mo>∼</k:mo> <k:mn>70</k:mn> <k:mspace width="0.16em"/> <k:mi mathvariant="normal">K</k:mi> </k:mrow> </k:math> feature represents a transition from a high-temperature ferromagnet to a low-temperature antiferromagnet. We suggest that these magnetic transitions are related to changes in the unit-cell dimensions and are connected to the temperature-dependent Hall resisitivity studied in two-dimensional heterostructures. This implies a link between structural, magnetic, and electronic properties in the “pseudo” two-dimensional chromium tellurides.