Paramagnetism-based remote temperature measurement method for magnetic nanoparticle

A method for paramagnetism-based remote temperature measurement of a measured object using magnetic nanoparticles, comprising:

• (1) positioning a sample of said magnetic nanoparticles at an area of said measured object;
• (2) applying n times of different excited magnetic fields on said area;
• (3) collecting magnetization of said sample under said different excited magnetic fields, and calculating magnetic susceptibility of said sample under said different excited magnetic fields according to said magnetization;
• (4) constructing equations between said magnetic susceptibility and said different excited magnetic fields
• 1
• χ
• i
• =
• H
• i
• NML
• 
• (
• MH
• i
• kT
• )
• ,
• 
• i
• =
• 1
• ,
• 2
• 
• 
• …
• 
• 
• n
• ,
• wherein:
• xi is said magnetic susceptibility;
• Hi is said different excited magnetic fields;
• reciprocal of the Langevin's function
• L
• 
• (
• MH
• i
• kT
• )
• 
• :
• 
• 
• 1
• L
• 
• (
• α
• )
• =
• ∑
• j
• =
• 0
• J
• 
• c
• 2
• 
• j
• -
• 1
• 
• α
• 2
• 
• j
• -
• 1
• 
• [
• [
• ,
• ]
• ]
• 
• ;
• _
• α
• =
• MH
• i
• kT
• 
• [
• [
• ,
• ]
• ]
• 
• ;
• _
• c2j−1 is a polynomial coefficient;
• J+1 is a predetermined polynomial expansion term;
• N is concentration of said sample;
• M is atomic magnetic moment of said sample;
• k is a Boltzmann's constant;
• and T is temperature of said measured object;
• (5) solving said equations to obtain said temperature T.