Uncompensated antiferromagnetic structure of Ho2Ni2Pb

Autor: J. A. Mydosh, E. Muñoz Sandoval, Aravind D. Chinchure, Karel Prokes
Rok vydání: 2005
Předmět:
Zdroj: The European Physical Journal B. 43:163-174
ISSN: 1434-6036
1434-6028
DOI: 10.1140/epjb/e2005-00039-1
Popis: We have studied the magnetic structure of the orthorhombic compound Ho2Ni2Pb by means of neutron diffraction in zero field and in magnetic fields up to 4.5 T. Both powder and single-crystalline samples were used. Previous bulk measurements suggest two distinct magnetic phase transitions: one at TN = 7.0 K and the other at 4.8 K. Our neutron diffraction measurements, which were made in the range 1.5-20 K, showed that Ho2Ni2Pb has a collinear magnetic structure with unequal number of up and down Ho moments that are aligned parallel and antiparallel to the c axis. At the lowest temperatures the Ho moments are equal in size, each 8.3 μB in agreement with magnetization data. The magnetic structure can be described as having a 5a ×b ×c magnetic unit cell. Below Ts = 3.0 K the structure is squared up. A smooth development of all the magnetic moment magnitudes indicates that the magnetic structure remains in principle the same over the whole temperature range, the “phase transition” around 4.8 K can be identified as an inflection point in the temperature dependence of one of the Ho moments. With increasing temperature there is a clear development towards a simple transverse sine-wave modulated magnetic structure that is established just below TN.
Databáze: OpenAIRE