The magnetization of the antiferromagnetic magnetoelectric LiNiPO₄ single crystal along the crystallographic axes a, b and c was measured. The carried out researches have shown in it presence of a weak ferromagnetism. The weak ferromagnetic moment is directed along the antiferromagnetic axis of the crystal. The measured remanent magnetization in LiNiPO₄ is equal to about 0.005 G at 5K. With increase of a temperature of the sample up to the Neel temperature (T_N~21K) the remanent magnetic moment was decreasing up to zero. Furthermore, in LiNiPO₄ the intermediate antiferromagnetic phase was revealed in the narrow temperature interval ~1 K near Neel temperature. The magnetic structure of the basic antiferromagnetic state of LiNiPO₄ is uniform, but its antiferromagnetic intermediate state has a modulated structure. For more information about processes of magnetic ordering the behaviour of birefringence in this crystal was investigated depending on changes of temperature or intensity of a magnetic field. So, on the temperature dependences of birefringence is observed jump at Т₁ and at Т₂ (=Т₁+1К) break of a curve. These features to make agree with presence intermediate of structure in a temperature interval Т₁-Т₂. But herewith the temperature hysteresis with width 6 K and the centre in the T_N is observed. In addition, we notice linear dependence of birefringence on intensity of a magnetic field in fields up to 15 kOe and further break of a curve. In higher magnetic fields, the dependence carries parabolic character. The attempt is made to connect these features with behaviour of magnetic structure in a magnetic field. (ilt.kharkov.ua/bvi/structure/depart_e/d04/resecher-en.html)

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/7723 must be provided.