Magnetic Properties and Magnetoresistance of HfFe6Ge6—Type Er1—xGdxMn6Ge6 and Ho1—xGdxMn6Ge6（0.2≤x≤0.9） Compounds

Magnetic properties and magnetoresistance effects of the Er1-xGdxMn6Ge6 and Ho1-xGdxMn6Ge6 (0.2≤x≤0.9) compounds have been studied by magnetic property and resistivity measurements in applied magnetic field up to 5T. For increasing Gd content, two series display a transition from the antiferromagnetic state to the ferrimagnetic state. The Er1-xGdxMn6Ge6 (x=0.2 and 0.5) and Ho1-xGdxMn6Ge6(x=0.2 and 0.4) compounds order antiferromagnetically at 430,432,423 and 425K, respectively. The Er1-xMn6Ge6 (x=0.8 and 0.9) and Ho1-xGdxMn6Ge6(x=0.7,0.8 and 0.9) compounds order ferrimagnetically at 462, 471, 450, 463 and 470K, respectively. The Er1-xGdxMn6Ge6 and Ho1-xGdxMn6Ge6 compounds undergo the second transitions below 71 and 82K, respectively. The magnetoresistance curves of the Er0.1Gd0.9Mn6Ge6 and Ho0.1Gd0.9Mn6Ge6 compounds in a field of 5T are presented and the magnetoresistance effects are related to the metamagnetic transistions.