Magnetic and structural properties of Nd2Fe17−xMnx solid solutions

A series of Nd2Fe17−xMnx solid solutions with x values between 0 and 6 were prepared and analyzed using magnetic measurements, neutron diffraction, and Mossbauer spectroscopy. All of the Nd2Fe17−xMnx samples crystallized in the Th2Zn17−x-type rhombohedral structure. The lattice parameters and unit cell volumes decrease with increasing manganese content up to ∼x equal to 2, and then increase for higher manganese content. The magnetizations of Nd2Fe17−xMnx decrease with increasing manganese content and Nd2Fe17−xMnx is paramagnetic at room temperature for x greater than 3. The Curie temperature in Nd2Fe17−xMnx solid solutions is maximum for x equal to 0.5 and decreases at a rate of ∼10° per substituted manganese up to x equal to 3, after which it drops sharply. These results are discussed in terms of the manganese site occupancies in Nd2Fe17−xMnx.