This behavior is an Temperature dependent Magnetization reversal, kindly see the attachment file, which would be helpful to you, it explains the mechanism of MR

thanks

First, it is very important to know in what fases this experiment was done. If in a gas, liquid or solid.

It was a solid, what size and structure of the material analyzed. After this review, I think we could define how the temperature affected the arrangement of magnetic cells, which are larger than the structural cells. However, the unit magnet may be parsed atom by atom.

Your experiment was done at a very low temperature range. In this range most materials behave in a specific anwers, not following expected function behavior.

Dear Muhammad,

  Near Tn , alignment of spin get disturb due to thermal properties (It said to be blocking temperature). Hence, future increasing temperature magnetization also reduce sharply and particular point it should minimum magnetization and get saturated (Tis point oly we said as neel temperature ). Generally , in RFeO3 compounds TB= 550 K - 590 K and Tn= 620 K-720 K. For your figure that point is Blocking temperature only. Still you need to increases temperature and see the neel temperature point. 

Respected Sir can we interpret these kind of reversed magnetization with the help of some technique like neutron powder diffraction at low temperature?

Neel temperature, usually called "Neel point" is not different  from its high-temperature counterpart "Curie point". However, both are not fixed " critical points", but temperature ranges of nucleation-growth phase transitions. While only relative quantities of the phases change over the range of transition, the illusion is created that the quality of the measured property is changing. See my book "Fundamentals of Solid-State Phase ...", in particular its Chapter 3 "Lambda-Anomalies" and Other Apparent Anomalies.

The Curie temperature (Tc) and Neel temperature (Tn) are similar in nature and represent the temperature above which no spin ordering is possible. These are material dependent parameters. In the literature Tc is often used to refer to Tn, but strictly Tn is for antiferromagnets.

The blocking temperature (Tb) on the other hand, is the temperature below which spin ordering is stable on laboratory timescale for a given grain. That is, it is the temperature below which magnetic remanence can be acquired by that grain.

Tb is grain volume dependent, such that for small grains thermal fluctuations are sufficient to overcome any ordering and the grain becomes superparamagnetic.

Tc and Tn represent the maximum possible Tb for a given material.

What you are measuring here is Tb, not Tn. Paul Blessington's answer about magnetization reversal is a strong possibility, but what material are you measuring?